US20120089774A1 - Method and system for mitigating adjacent track erasure in hard disk drives - Google Patents

Method and system for mitigating adjacent track erasure in hard disk drives Download PDF

Info

Publication number
US20120089774A1
US20120089774A1 US12/902,150 US90215010A US2012089774A1 US 20120089774 A1 US20120089774 A1 US 20120089774A1 US 90215010 A US90215010 A US 90215010A US 2012089774 A1 US2012089774 A1 US 2012089774A1
Authority
US
United States
Prior art keywords
blocks
hard disk
processor
categories
content
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US12/902,150
Inventor
Bhooshan P. Kelkar
Abhinay R. Nagpal
Sandeep R. Patil
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US12/902,150 priority Critical patent/US20120089774A1/en
Assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION reassignment INTERNATIONAL BUSINESS MACHINES CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: PATIL, SANDEEP R., KELKAR, BHOOSHAN P., NAGPAL, ABHINAY R.
Assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION reassignment INTERNATIONAL BUSINESS MACHINES CORPORATION CORRECTIVE ASSIGNMENT TO CORRECT THE ADDRESS OF ASSIGNEE PREVIOUSLY RECORDED ON REEL 025121 FRAME 0607. ASSIGNOR(S) HEREBY CONFIRMS THE NEW ORCHARD ROAD. Assignors: PATIL, SANDEEP R., KELKAR, BHOOSHAN P., NAGPAL, ABHINAY R.
Priority to CN201110304599.4A priority patent/CN102446511B/en
Priority to TW100136816A priority patent/TW201229758A/en
Publication of US20120089774A1 publication Critical patent/US20120089774A1/en
Priority to US13/935,119 priority patent/US8914573B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/12—Formatting, e.g. arrangement of data block or words on the record carriers
    • G11B20/1217—Formatting, e.g. arrangement of data block or words on the record carriers on discs
    • G11B20/1258—Formatting, e.g. arrangement of data block or words on the record carriers on discs where blocks are arranged within multiple radial zones, e.g. Zone Bit Recording or Constant Density Recording discs, MCAV discs, MCLV discs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
    • G11B19/02—Control of operating function, e.g. switching from recording to reproducing
    • G11B19/04—Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
    • G11B19/041—Detection or prevention of read or write errors
    • G11B19/045—Detection or prevention of read or write errors by detecting mistracking
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00666—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving a step of erasing or nullifying data, e.g. data being overwritten with a random string
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/012—Recording on, or reproducing or erasing from, magnetic disks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00—Record carriers by type
    • G11B2220/20—Disc-shaped record carriers
    • G11B2220/25—Disc-shaped record carriers characterised in that the disc is based on a specific recording technology
    • G11B2220/2508—Magnetic discs
    • G11B2220/2516—Hard disks

Definitions

  • a hard disk drive includes one or more hard disks clamped to a rotating spindle and at least one head for reading or writing data on the disk. Storage on a hard disk is divided into “blocks”, which are in turn grouped into “tracks”. A disk head uses magnetism to read or write data onto the tracks. Secure deletion involves the overwriting of blocks on a track by the disk head numerous times, depending on the standard being applied. Thus, secure deletion involves multiple input/output (I/O) operations on the same blocks of a track.
  • I/O input/output
  • adjacent tracks may be overwritten by the magnetic field generated in the disk head, and data recorded in the adjacent tracks may be erased or corrupted as a result.
  • This phenomenon is called adjacent track erasure (ATE) or adjacent track interference (ATI) and are aggravated by the multiple overwrites required by secure deletion.
  • a method for mitigating adjacent track erasures in hard disks the computer operationally coupled to a processor, the method comprising: determining input/output (I/O) characteristics for a plurality of blocks on a hard disk by the processor; assigning the plurality of blocks to a plurality of categories of I/O characteristics by the processor; and clustering content of the blocks assigned to the same category in one or more continuous tracks on the hard disk by the processor.
  • I/O input/output
  • the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises determining secure deletion requirements for the plurality of blocks on the hard disk by the processor, the secure deletion requirements comprising overwriting rates for the plurality of blocks;
  • the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises assigning the plurality of blocks to a plurality of categories associated with the overwriting rates;
  • the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises clustering the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk by the processor.
  • the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises determining expected access frequencies for a given time period for the plurality of blocks on the hard disk by the processor; the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises: assigning the plurality of blocks to a plurality of categories of expected access frequencies for the given time period by the processor; and the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: clustering the content of the blocks assigned to the same category of expected access frequency in the one or more continuous tracks on the hard disk by the processor.
  • the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises assigning a plurality of counters for the plurality of blocks of the hard disk by the processor, and for each of the plurality of blocks, incrementing by the processor the counter for the block each time a read operation or a write operation is performed on the block;
  • the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises assigning one of the plurality of categories to each of the plurality of blocks by the processor, wherein the plurality of categories are defined based on thresholds of the plurality of counter values;
  • the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises clustering the content of the blocks assigned the same counter value category in the one or more continuous tracks on the hard disk by the processor.
  • the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises maintaining a table comprising a number of accesses and remanence states of the plurality of blocks on the hard disk by the processor;
  • the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises defining a space by the processor representing the plurality of blocks with attribute dimensions comprising the number of accesses, time, and the remanence states, placing objects representing the plurality of blocks within the space by the processor, and applying a K-means clustering algorithm on the objects by the processor using a plurality of categories of the attribute dimensions as classes;
  • the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: storing the content of the plurality of blocks in each cluster in the space in the one or more continuous tracks on the hard disk by the processor.
  • the method further comprises: performing at least one overwrite operation on at least one of the plurality of blocks of a track on the hard disk by the processor; determining by the processor if a predetermined threshold of overwrites for the block is reached; and in response to determining that the predetermined threshold of overwrites for the block is reached, refreshing content of adjacent tracks by the processor.
  • FIG. 1 illustrates an embodiment of a system for mitigating adjacent track erasures in hard disks according to the present invention.
  • FIG. 2 is a flowchart illustrating an embodiment of a method for mitigating adjacent track erasures in hard disks according to the present invention.
  • FIG. 3 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks for secure deletion, according to the present invention.
  • FIG. 4 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks using a time dimension according to the present invention.
  • FIG. 5 is a flowchart illustrating an embodiment of the determining of the I/O characteristics of the plurality of blocks according to the present invention.
  • FIG. 6 is a flowchart illustrating an embodiment of the clustering of the plurality of blocks according to the present invention.
  • aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
  • the computer readable medium may be a computer readable signal medium or a computer readable storage medium.
  • a computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.
  • a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
  • a computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof.
  • a computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
  • Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
  • Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as JavaTM (Java, and all Java-based trademarks and logos are trademarks of Sun Microsystems, Inc. in the United States, other countries, or both), Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages.
  • the program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server.
  • the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
  • LAN local area network
  • WAN wide area network
  • Internet Service Provider an Internet Service Provider
  • These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
  • the computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
  • each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified local function(s).
  • the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.
  • FIG. 1 illustrates an embodiment of a system for mitigating adjacent track erasures in hard disks according to the present invention.
  • the system comprises a computer 101 operationally coupled to a hard disk drive comprising one or more hard disks 105 , where data is read and written to tracks on the hard disk 105 by a disk head 106 .
  • the computer 101 is further operationally coupled to a processor 102 and a computer readable medium 103 .
  • the computer readable medium 103 stores computer readable program code 104 for implementing the method of the present invention.
  • the processor 102 executes the program code 104 to mitigate adjacent track erasure in hard disks 105 according to the various embodiments of the present invention.
  • FIG. 2 is a flowchart illustrating an embodiment of a method for mitigating adjacent track erasures in hard disks according to the present invention.
  • the method determines the I/O characteristics for a plurality of blocks on the hard disk 105 ( 201 ).
  • the method then assigns the blocks to categories of I/O characteristics ( 202 ).
  • the content of blocks assigned the same category are clustered in one or more continuous tracks on the hard disk 105 ( 203 ).
  • the clustering of the blocks may be performed by moving the content to the continuous tracks, or by taking the assigned category into account when the block is initially written. In this embodiment, each block is assigned to one category. Blocks with similar I/O characteristics are thus clustered on one or more continuous tracks.
  • blocks with a high number of I/O operations are grouped and stored on fewer tracks than if they were scattered across numerous tracks. This reduces the number of tracks experiencing a high number of I/O operations, and in turn, the amount of refreshing of adjacent tracks is reduced.
  • the I/O characteristics comprise the access frequency of the plurality of blocks.
  • the method determines the access frequencies of each block on the hard disk 105 ( 201 ). Blocks with high access frequencies are assigned to the same high access frequency category, while blocks with low access frequencies are assigned to the same low access frequency category ( 202 ).
  • An example of high access frequency blocks include blocks storing a current time, where the current time is rewritten at regular intervals.
  • the content of the blocks assigned to the same high access frequency category are then clustered in one or more continuous tracks ( 203 ). Only the tracks adjacent to the tracks storing the high access frequency blocks will be refreshed frequently.
  • the content of the blocks assigned to the same low access frequency category are clustered in another set of continuous tracks ( 203 ). The tracks adjacent to the tracks storing the low access frequency blocks would be refreshed less frequently.
  • FIG. 3 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks for secure deletion, according to the present invention.
  • the method determines the secure deletion requirements for a plurality of blocks of the hard disk 105 , where the secure deletion requirements comprise overwriting rates for the blocks ( 301 ).
  • the method assigns the blocks to categories associated with the overwriting rates ( 302 ).
  • the content of the blocks assigned the same overwriting rate category are clustered in one or more continuous tracks on the hard disk 105 ( 303 ).
  • the secure deletion requirements may be set by government regulation or by any other security standards.
  • the blocks in tracks storing the file are overwritten at least ten times.
  • the method determines if the overwriting of the blocks have reached a predetermined threshold of overwrites, defined to determine when ATI or ATE may become a problem for adjacent tracks. In response to determining that the predetermined threshold has been reached, the content of the adjacent tracks are refreshed.
  • the I/O characteristics comprise a time dimension, where the access frequencies of blocks may vary from time period to time period.
  • FIG. 4 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks using a time dimension according to the present invention.
  • the method determines the expected access frequencies for a given time period for the plurality of blocks ( 401 ).
  • the method assigns the blocks to categories of expected access frequencies for the given time period ( 402 ).
  • the content of the blocks assigned the same expected access frequency category are then clustered in one more continuous tracks on the hard disk 105 ( 403 ).
  • the method determines that these blocks are expected to have high access frequencies for the Thanksgiving holiday ( 401 ). During the Thanksgiving holiday, the method assigns these blocks to the same high access frequency category ( 402 ). The content of the blocks, i.e., the files containing the Thanksgiving offers, are then clustered in continuous tracks of the hard disk 105 ( 403 ). By clustering the blocks in this manner, only two adjacent tracks need to be refreshed, as opposed to ten adjacent racks if the blocks remained scattered.
  • FIG. 5 is a flowchart illustrating an embodiment of the determining of the I/O characteristics of the plurality of blocks according to the present invention.
  • the method assigns counters for the plurality of blocks of the hard disk 105 ( 501 ).
  • the counter may be stored in a table. In this embodiment, there is one counter for each block.
  • the method assigns a category to each block, where categories are defined based on thresholds of counter values ( 503 ).
  • the method clusters the content of the blocks assigned to the same counter value category in one or more continuous tracks on the hard disk 105 ( 504 ).
  • FIG. 6 is a flowchart illustrating an embodiment of the clustering of the plurality of blocks according to the present invention.
  • the method maintains a table of the number of accesses and the remanence states of the plurality of blocks on the hard disk 105 ( 601 ).
  • the method defines a space representing the blocks with the following attribute dimensions: number of accesses, time, and remanence state ( 602 ). For example, these dimensions can define the X, Y, and Z-axes of a three dimensional space.
  • Objects representing the blocks are placed within the space ( 603 ).
  • the K-Means clustering algorithm is then applied on the objects using categories of the attribute dimensions as the classes ( 604 ).
  • K-means is an unsupervised learning algorithm that solves clustering problems.
  • the algorithm classifies a given data set through a certain number (k) of clusters fixed a priori.
  • K centroids are defined, one for each cluster. Each point belonging to a given data set is assigned to the nearest centroid. K new centroids are then re-calculated as barycenters of the clusters resulting from the previous step. A new binding is then done between the same data set points and the nearest new centroid.
  • a loop is thus generated. As a result of this loop, the k centroids change their locations step by step until no more changes occur, i.e., the centroids do not move any more.
  • the K-Means clustering algorithm is known in the art and will not be described further here.
  • the application of the K-Means algorithm results in the clustering of blocks with similar or same attribute dimensions.
  • the content of the blocks in each cluster in the space are then stored in one or more continuous tracks on the hard disk 105 ( 604 ).
  • the availability of continuous tracks on the hard disk 105 may be determined in a variety of ways. For example, on Direct Access Storage Devices (DASD), the availability of storage blocks within a storage subpool is recorded in an allocation control structure. Storage subpools are divided into allocation units which contain a fixed number of consecutive DASD storage blocks. Storage subpools are divided into allocation units to reduce the amount of data needed to record the availability of storage blocks. Storage is allocated to a requesting function in extents of consecutive allocation units. An extent of allocated storage is formed from a number of consecutive allocation units.
  • DASD Direct Access Storage Devices
  • the allocation units forming any allocated extent belong to the same storage subpool, and the storage blocks within an extent are consecutive DASD storage blocks. Extents allocated for use of the working store consist of fixed number of working storage allocation units. Any subpool block is accessed by a relative data set identifier and a relative block number within the data set. Space allocation on DASD using an allocation control structure is known in the art and will not be described further here.
  • Blocks on a hard disk are assigned categories of I/O characteristics, and blocks assigned to the same category are clustered on one or more continuous tracks. By performing this clustering, blocks with a high number of I/O operations are grouped and stored on fewer tracks than if they were scattered cross numerous tracks. This reduces the number of tracks experiencing a high number of I/O operations, and in turn, the amount of refreshing of adjacent racks is reduced.

Abstract

A method, system, and computer program product for mitigating adjacent track erasures in hard disks, includes: determining input/output (I/O) characteristics for a plurality of blocks on a hard disk; assigning the plurality of blocks to a plurality of categories of I/O characteristics by the processor; and clustering content of the blocks assigned to the same category in one or more continuous tracks on the hard disk. Each block is assigned to one category. Blocks with similar I/O characteristics are clustered on one or more continuous tracks. By performing this clustering, blocks with a high number of I/O operations are grouped and stored on fewer tracks than if they were scattered across numerous tracks. This reduces the number of tracks experiencing a high number of I/O operations, and in turn, the amount of refreshing of adjacent tracks is reduced.

Description

    BACKGROUND
  • Secure deletion of data on non-volatile magnetic data storage, such as a hard disk, is an act of securely purging the data such that there are no residuals of the data on the hard disk. Regulations exist which mandate the need for secure deletion according to various standards, such as that published by the U.S. Department of Defense. A hard disk drive includes one or more hard disks clamped to a rotating spindle and at least one head for reading or writing data on the disk. Storage on a hard disk is divided into “blocks”, which are in turn grouped into “tracks”. A disk head uses magnetism to read or write data onto the tracks. Secure deletion involves the overwriting of blocks on a track by the disk head numerous times, depending on the standard being applied. Thus, secure deletion involves multiple input/output (I/O) operations on the same blocks of a track.
  • As a track on the hard disk is written, adjacent tracks may be overwritten by the magnetic field generated in the disk head, and data recorded in the adjacent tracks may be erased or corrupted as a result. This phenomenon is called adjacent track erasure (ATE) or adjacent track interference (ATI) and are aggravated by the multiple overwrites required by secure deletion.
  • In one approach to counter ATE or ATI, when a track has been overwritten a certain number of times, the adjacent tracks are read and rewritten, hence refreshing the data on the adjacent tracks. However, the I/O operations required in the refreshing of the adjacent tracks impose a performance penalty on the hard disk drive. With the aggravation of the ATE and ATI phenomenon due to secure deletion requirements, the need to refresh adjacent tracks become more frequent, imposing an even high performance penalty on the hard disk drive.
    • BRIEF SUMMARY
  • According to one embodiment of the present invention, a method for mitigating adjacent track erasures in hard disks, the computer operationally coupled to a processor, the method comprising: determining input/output (I/O) characteristics for a plurality of blocks on a hard disk by the processor; assigning the plurality of blocks to a plurality of categories of I/O characteristics by the processor; and clustering content of the blocks assigned to the same category in one or more continuous tracks on the hard disk by the processor.
  • In one aspect of the present invention, the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises determining secure deletion requirements for the plurality of blocks on the hard disk by the processor, the secure deletion requirements comprising overwriting rates for the plurality of blocks; the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises assigning the plurality of blocks to a plurality of categories associated with the overwriting rates; and the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises clustering the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk by the processor.
  • In one aspect of the present invention, the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises determining expected access frequencies for a given time period for the plurality of blocks on the hard disk by the processor; the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises: assigning the plurality of blocks to a plurality of categories of expected access frequencies for the given time period by the processor; and the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: clustering the content of the blocks assigned to the same category of expected access frequency in the one or more continuous tracks on the hard disk by the processor.
  • In one aspect of the present invention, the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises assigning a plurality of counters for the plurality of blocks of the hard disk by the processor, and for each of the plurality of blocks, incrementing by the processor the counter for the block each time a read operation or a write operation is performed on the block; the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises assigning one of the plurality of categories to each of the plurality of blocks by the processor, wherein the plurality of categories are defined based on thresholds of the plurality of counter values; the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises clustering the content of the blocks assigned the same counter value category in the one or more continuous tracks on the hard disk by the processor.
  • In one aspect of the present invention, the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises maintaining a table comprising a number of accesses and remanence states of the plurality of blocks on the hard disk by the processor; the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises defining a space by the processor representing the plurality of blocks with attribute dimensions comprising the number of accesses, time, and the remanence states, placing objects representing the plurality of blocks within the space by the processor, and applying a K-means clustering algorithm on the objects by the processor using a plurality of categories of the attribute dimensions as classes; the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: storing the content of the plurality of blocks in each cluster in the space in the one or more continuous tracks on the hard disk by the processor.
  • In one aspect of the present invention, the method further comprises: performing at least one overwrite operation on at least one of the plurality of blocks of a track on the hard disk by the processor; determining by the processor if a predetermined threshold of overwrites for the block is reached; and in response to determining that the predetermined threshold of overwrites for the block is reached, refreshing content of adjacent tracks by the processor.
  • System and computer program products corresponding to the above-summarized methods are also described and claimed herein.
    • BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
  • FIG. 1 illustrates an embodiment of a system for mitigating adjacent track erasures in hard disks according to the present invention.
  • FIG. 2 is a flowchart illustrating an embodiment of a method for mitigating adjacent track erasures in hard disks according to the present invention.
  • FIG. 3 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks for secure deletion, according to the present invention.
  • FIG. 4 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks using a time dimension according to the present invention.
  • FIG. 5 is a flowchart illustrating an embodiment of the determining of the I/O characteristics of the plurality of blocks according to the present invention.
  • FIG. 6 is a flowchart illustrating an embodiment of the clustering of the plurality of blocks according to the present invention.
    •  DETAILED DESCRIPTION
  • As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
  • Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
  • A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
  • Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
  • Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java™ (Java, and all Java-based trademarks and logos are trademarks of Sun Microsystems, Inc. in the United States, other countries, or both), Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
  • Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer special purpose computer or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
  • These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
  • The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
  • The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified local function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
  • The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
  • The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.
  • FIG. 1 illustrates an embodiment of a system for mitigating adjacent track erasures in hard disks according to the present invention. The system comprises a computer 101 operationally coupled to a hard disk drive comprising one or more hard disks 105, where data is read and written to tracks on the hard disk 105 by a disk head 106. The computer 101 is further operationally coupled to a processor 102 and a computer readable medium 103. The computer readable medium 103 stores computer readable program code 104 for implementing the method of the present invention. The processor 102 executes the program code 104 to mitigate adjacent track erasure in hard disks 105 according to the various embodiments of the present invention.
  • FIG. 2 is a flowchart illustrating an embodiment of a method for mitigating adjacent track erasures in hard disks according to the present invention. The method determines the I/O characteristics for a plurality of blocks on the hard disk 105 (201). The method then assigns the blocks to categories of I/O characteristics (202). The content of blocks assigned the same category are clustered in one or more continuous tracks on the hard disk 105 (203). The clustering of the blocks may be performed by moving the content to the continuous tracks, or by taking the assigned category into account when the block is initially written. In this embodiment, each block is assigned to one category. Blocks with similar I/O characteristics are thus clustered on one or more continuous tracks. By performing this clustering, blocks with a high number of I/O operations are grouped and stored on fewer tracks than if they were scattered across numerous tracks. This reduces the number of tracks experiencing a high number of I/O operations, and in turn, the amount of refreshing of adjacent tracks is reduced.
  • In one embodiment, the I/O characteristics comprise the access frequency of the plurality of blocks. The method determines the access frequencies of each block on the hard disk 105 (201). Blocks with high access frequencies are assigned to the same high access frequency category, while blocks with low access frequencies are assigned to the same low access frequency category (202). An example of high access frequency blocks include blocks storing a current time, where the current time is rewritten at regular intervals. The content of the blocks assigned to the same high access frequency category are then clustered in one or more continuous tracks (203). Only the tracks adjacent to the tracks storing the high access frequency blocks will be refreshed frequently. The content of the blocks assigned to the same low access frequency category are clustered in another set of continuous tracks (203). The tracks adjacent to the tracks storing the low access frequency blocks would be refreshed less frequently.
  • For example, assume that frequently accessed files are stored in blocks scattered across five tracks, requiring the refreshing of ten adjacent tracks. However, when these blocks are clustered in one track, only two adjacent tracks need to be refreshed, resulting in a gain in performance.
  • In another embodiment, the I/O characteristics pertain to the requirements for the secure deletion of files. FIG. 3 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks for secure deletion, according to the present invention. In this embodiment, the method determines the secure deletion requirements for a plurality of blocks of the hard disk 105, where the secure deletion requirements comprise overwriting rates for the blocks (301). The method assigns the blocks to categories associated with the overwriting rates (302). The content of the blocks assigned the same overwriting rate category are clustered in one or more continuous tracks on the hard disk 105 (303). The secure deletion requirements may be set by government regulation or by any other security standards.
  • For example, assume that a file stored on blocks scattered across five tracks is classified as high security, and the method determines that regulations require a rate of ten overwrites to the blocks to facilitate its secure deletion (301). Categories for different thresholds of overwrites are defined, and the blocks for this file are assigned to the same ten-overwrites-or-over category (302). The content of these blocks, i.e., the high security file, are then clustered in one or more continuous tracks of the hard disk 105 (303). By clustering these blocks in this manner, only two adjacent tracks need to be refreshed, as opposed to ten adjacent tracks if the blocks remained scattered.
  • When the secure deletion of the high security file is performed, the blocks in tracks storing the file are overwritten at least ten times. The method determines if the overwriting of the blocks have reached a predetermined threshold of overwrites, defined to determine when ATI or ATE may become a problem for adjacent tracks. In response to determining that the predetermined threshold has been reached, the content of the adjacent tracks are refreshed.
  • In another embodiment, the I/O characteristics comprise a time dimension, where the access frequencies of blocks may vary from time period to time period. FIG. 4 is a flowchart illustrating an embodiment of the method for mitigating adjacent track erasures in hard disks using a time dimension according to the present invention. The method determines the expected access frequencies for a given time period for the plurality of blocks (401). The method assigns the blocks to categories of expected access frequencies for the given time period (402). The content of the blocks assigned the same expected access frequency category are then clustered in one more continuous tracks on the hard disk 105 (403).
  • For example, assume that files containing Thanksgiving offers are stored on blocks scattered across five tracks. For the time period defined for the Thanksgiving holiday, the method determines that these blocks are expected to have high access frequencies for the Thanksgiving holiday (401). During the Thanksgiving holiday, the method assigns these blocks to the same high access frequency category (402). The content of the blocks, i.e., the files containing the Thanksgiving offers, are then clustered in continuous tracks of the hard disk 105 (403). By clustering the blocks in this manner, only two adjacent tracks need to be refreshed, as opposed to ten adjacent racks if the blocks remained scattered.
  • Although the embodiment are described with the I/O characteristics above, one of ordinary skill in the art will understand that a variety of I/O characteristics of the plurality of blocks may be used, alone or in combination, without departing from the spirit and scope of the present invention.
  • FIG. 5 is a flowchart illustrating an embodiment of the determining of the I/O characteristics of the plurality of blocks according to the present invention. The method assigns counters for the plurality of blocks of the hard disk 105 (501). For example, the counter may be stored in a table. In this embodiment, there is one counter for each block. Each time a read or write operation is performed on a block, the block's counter is incremented (502). The method assigns a category to each block, where categories are defined based on thresholds of counter values (503). The method clusters the content of the blocks assigned to the same counter value category in one or more continuous tracks on the hard disk 105 (504).
  • FIG. 6 is a flowchart illustrating an embodiment of the clustering of the plurality of blocks according to the present invention. The method maintains a table of the number of accesses and the remanence states of the plurality of blocks on the hard disk 105 (601). The method defines a space representing the blocks with the following attribute dimensions: number of accesses, time, and remanence state (602). For example, these dimensions can define the X, Y, and Z-axes of a three dimensional space. Objects representing the blocks are placed within the space (603). The K-Means clustering algorithm is then applied on the objects using categories of the attribute dimensions as the classes (604).
  • K-means is an unsupervised learning algorithm that solves clustering problems. The algorithm classifies a given data set through a certain number (k) of clusters fixed a priori. K centroids are defined, one for each cluster. Each point belonging to a given data set is assigned to the nearest centroid. K new centroids are then re-calculated as barycenters of the clusters resulting from the previous step. A new binding is then done between the same data set points and the nearest new centroid. A loop is thus generated. As a result of this loop, the k centroids change their locations step by step until no more changes occur, i.e., the centroids do not move any more. This algorithm aims at minimizing an object function, such as V=Σi=1 kΣkjεS i (xj−μi)2, where there are k clusters=Si, where i=1, 2, . . . k, and μi is the centroid or mean point of all the point xiεSi. The K-Means clustering algorithm is known in the art and will not be described further here.
  • The application of the K-Means algorithm results in the clustering of blocks with similar or same attribute dimensions. The content of the blocks in each cluster in the space are then stored in one or more continuous tracks on the hard disk 105 (604). The availability of continuous tracks on the hard disk 105 may be determined in a variety of ways. For example, on Direct Access Storage Devices (DASD), the availability of storage blocks within a storage subpool is recorded in an allocation control structure. Storage subpools are divided into allocation units which contain a fixed number of consecutive DASD storage blocks. Storage subpools are divided into allocation units to reduce the amount of data needed to record the availability of storage blocks. Storage is allocated to a requesting function in extents of consecutive allocation units. An extent of allocated storage is formed from a number of consecutive allocation units. The allocation units forming any allocated extent belong to the same storage subpool, and the storage blocks within an extent are consecutive DASD storage blocks. Extents allocated for use of the working store consist of fixed number of working storage allocation units. Any subpool block is accessed by a relative data set identifier and a relative block number within the data set. Space allocation on DASD using an allocation control structure is known in the art and will not be described further here.
  • Although the embodiment above is described using the K-means clustering algorithm, one of ordinary skill in the art will understand that other methods of clustering may be used without departing from the spirit and scope of the present invention.
  • A method, system, and computer program product for mitigating adjacent track erasures in hard disks have been disclosed. Blocks on a hard disk are assigned categories of I/O characteristics, and blocks assigned to the same category are clustered on one or more continuous tracks. By performing this clustering, blocks with a high number of I/O operations are grouped and stored on fewer tracks than if they were scattered cross numerous tracks. This reduces the number of tracks experiencing a high number of I/O operations, and in turn, the amount of refreshing of adjacent racks is reduced.
  • Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.

Claims (23)

1. A method implemented by a computing device for mitigating adjacent track erasures in hard disks, the computing device operationally coupled to a processor, the method comprising:
determining input/output (I/O) characteristics for a plurality of blocks on a hard disk by the processor;
assigning the plurality of blocks to a plurality of categories of I/O characteristics by the processor; and
clustering content of the blocks assigned to the same category in one or more continuous tracks on the hard disk by the processor.
2. The method of claim 1, wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises: determining secure deletion requirements for the plurality of blocks on the hard disk by the processor, the secure deletion requirements comprising overwriting rates for the plurality of blocks;
wherein the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises: assigning the plurality of blocks to a plurality of categories associated with the overwriting rates; and
wherein the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: clustering the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk by the processor.
3. The method of claim 1, wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises: determining expected access frequencies for a given time period for the plurality of blocks on the hard disk by the processor;
wherein the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises: assigning the plurality of blocks to a plurality of categories of expected access frequencies for the given time period by the processor; and
wherein the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: clustering the content of the blocks assigned to the same category of expected access frequency in the one or more continuous tracks on the hard disk by the processor.
4. The method of claim 1, wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises:
assigning a plurality of counters for the plurality of blocks of the hard disk by the processor, and
for each of the plurality of blocks, incrementing by the processor the counter for the block each time a read operation or a write operation is performed on the block;
wherein the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises: assigning one of the plurality of categories to each of the plurality of blocks by the processor, wherein the plurality of categories are defined based on thresholds of the plurality of counter values;
wherein the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: clustering the content of the blocks assigned the same counter value category in the one or more continuous tracks on the hard disk by the processor.
5. The method of claim 1, wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor comprises: maintaining a table comprising a number of accesses and remanence states of the plurality of blocks on the hard disk by the processor;
wherein the assigning the plurality of blocks to the plurality of categories of I/O characteristics by the processor comprises:
defining a space by the processor representing the plurality of blocks with attribute dimensions comprising the number of accesses, time, and the remanence states,
placing objects representing the plurality of blocks within the space by the processor, and
applying a K-means clustering algorithm on the objects by the processor using a plurality of categories of the attribute dimensions as classes;
wherein the clustering the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk by the processor comprises: storing the content of the plurality of blocks in each cluster in the space in the one or more continuous tracks on the hard disk by the processor.
6. The method of claim 1, further comprising:
performing at least one overwrite operation on at least one of the plurality of blocks of a track on the hard disk by the processor;
determining by the processor if a predetermined threshold of overwrites for the block is reached; and
in response to determining that the predetermined threshold of overwrites for the block is reached, refreshing content of adjacent tracks by the processor.
7. A computer program product for mitigating adjacent track erasure in hard disks, the computer program product comprising:
a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to:
determine input/output (I/O) characteristics for a plurality of blocks on a hard disk;
assign the plurality of blocks to a plurality of categories of I/O characteristics; and
cluster content of the blocks assigned to the same category in one or more continuous tracks on the hard disk.
8. The computer program product of claim 7, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to: determine secure deletion requirements for the plurality of blocks on the hard disk, the secure deletion requirements comprising overwriting rates for the plurality of blocks;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to: assign the plurality of blocks to a plurality of categories associated with the overwriting rates; and
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: cluster the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk.
9. The computer program product of claim 7, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to: determine expected access frequencies for a given time period for the plurality of blocks on the hard disk;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to: assign the plurality of blocks to a plurality of categories of expected access frequencies for the given time period; and
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: cluster the content of the blocks assigned to the same category of expected access frequency in the one or more continuous tracks on the hard disk.
10. The computer program product of claim 7, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to:
assign a plurality of counters for the plurality of blocks of the hard disk, and
for each of the plurality of blocks, increment the counter for the block each time a read operation or a write operation is performed on the block;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to: assign one of the plurality of categories to each of the plurality of blocks, wherein the plurality of categories are defined based on thresholds of the plurality of counter values;
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: cluster the content of the blocks assigned the same counter value category in the one or more continuous tracks on the hard disk.
11. The computer program product of claim 7, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to: maintain a table comprising a number of accesses and remanence states of the plurality of blocks on the hard disk;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to:
define a space representing the plurality of blocks with attribute dimensions comprising the number of accesses, time, and the remanence states,
place objects representing the plurality of blocks within the space, and
apply a K-means clustering algorithm on the objects using a plurality of categories of the attribute dimensions as classes;
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: store the content of the plurality of blocks in each cluster in the space in the one or more continuous tracks on the hard disk.
12. The computer program product of claim 7, wherein computer readable program code is further configured to:
perform at least one overwrite operation on at least one of the plurality of blocks of a track on the hard disk;
determine if a predetermined threshold of overwrites for the block is reached; and
in response to determining that the predetermined threshold of overwrites for the block is reached, refresh content of adjacent tracks.
13. A system comprising:
at least one hard disk comprising a plurality of tracks, each track comprising a plurality of blocks;
a processor; and
a computer readable storage medium operationally coupled to the processor, the computer readable storage medium having computer readable program code embodied therewith to be executed by the processor, the computer readable program code configured to:
determine input/output (I/O) characteristics for the plurality of blocks on the hard disk;
assign the plurality of blocks to a plurality of categories of I/O characteristics; and
cluster content of the blocks assigned to the same category in one or more continuous tracks of the plurality of tracks on the hard disk.
14. The system of claim 13, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to: determine secure deletion requirements for the plurality of blocks on the hard disk, the secure deletion requirements comprising overwriting rates for the plurality of blocks;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to: assign the plurality of blocks to a plurality of categories associated with the overwriting rates; and
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: cluster the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk.
15. The system of claim 13, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to: determine expected access frequencies for a given time period for the plurality of blocks on the hard disk;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to: assign the plurality of blocks to a plurality of categories of expected access frequencies for the given time period; and
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: cluster the content of the blocks assigned to the same category of expected access frequency in the one or more continuous tracks on the hard disk.
16. The system of claim 13, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to:
assign a plurality of counters for the plurality of blocks of the hard disk, and
for each of the plurality of blocks, increment the counter for the block each time a read operation or a write operation is performed on the block;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to: assign one of the plurality of categories to each of the plurality of blocks, wherein the plurality of categories are defined based on thresholds of the plurality of counter values;
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: cluster the content of the blocks assigned the same counter value category in the one or more continuous tracks on the hard disk.
17. The system of claim 13, wherein the computer readable program code configured to determine the I/O characteristics for the plurality of blocks on the hard disk is further configured to: maintain a table comprising a number of accesses and remanence states of the plurality of blocks on the hard disk;
wherein the computer readable program code configured to assign the plurality of blocks to the plurality of categories of I/O characteristics is further configured to:
define a space representing the plurality of blocks with attribute dimensions comprising the number of accesses, time, and the remanence states,
place objects representing the plurality of blocks within the space, and
apply a K-means clustering algorithm on the objects using a plurality of categories of the attribute dimensions as classes;
wherein the computer readable program code configured to cluster the content of the blocks assigned to the same category in the one or more continuous tracks on the hard disk is further configured to: store the content of the plurality of blocks in each cluster in the space in the one or more continuous tracks on the hard disk.
18. The system of claim 13, wherein computer readable program code is further configured to:
perform at least one overwrite operation on at least one of the plurality of blocks of a track on the hard disk;
determine if a predetermined threshold of overwrites for the block is reached; and
in response to determining that the predetermined threshold of overwrites for the block is reached, refresh content of adjacent tracks.
19. A computer implemented method for mitigating adjacent track erasures in hard disks, the computer operationally coupled to a processor, the method comprising:
determining input/output (I/O) characteristics for a plurality of blocks on the hard disk by the processor, the I/O characteristics comprising secure deletion requirements, the secure deletion requirements comprising overwriting rates for the plurality of blocks;
assigning the plurality of blocks to a plurality of categories associated with the overwriting rates by the processor; and
clustering content of the blocks assigned to the same overwriting rate category in one or more continuous tracks on the hard disk by the processor.
20. The method of claim 19, wherein the I/O characteristics further comprises expected access frequencies for a given time period for the plurality of blocks on the hard disk,
wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor, the I/O characteristics comprising secure deletion requirements, the secure deletion requirements comprising the overwriting rates for the plurality of blocks, further comprises: determining the expected access frequencies for the given time period for the plurality of blocks on the hard disk by the processor;
wherein the assigning the plurality of blocks to the plurality of categories associated with the overwriting rates by the processor further comprises: assigning the plurality of blocks to a plurality of categories of expected access frequencies for the given time period by the processor; and
wherein the clustering the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk by the processor further comprises: clustering the content of the blocks assigned to the same category of expected access frequency in the one or more continuous tracks on the hard disk by the processor.
21. The method of claim 19, wherein the I/O characteristics further comprises counter values for the plurality of blocks on the hard disk,
wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor, the I/O characteristics comprising secure deletion requirements, the secure deletion requirements comprising the overwriting rates for the plurality of blocks, further comprises:
assigning a plurality of counters for the plurality of blocks of the hard disk by the processor, and
for each of the plurality of blocks, incrementing by the processor the counter for the block each time a read operation or a write operation is performed on the block;
wherein the assigning the plurality of blocks to the plurality of categories associated with the overwriting rates by the processor further comprises: assigning one of the plurality of categories to each of the plurality of blocks by the processor, wherein the plurality of categories are defined based on thresholds of the plurality of counter values;
wherein the clustering the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk by the processor further comprises: clustering the content of the blocks assigned the same counter value category in the one or more continuous tracks on the hard disk by the processor.
22. The method of claim 19, wherein the determining the I/O characteristics for the plurality of blocks on the hard disk by the processor, the I/O characteristics comprising secure deletion requirements, the secure deletion requirements comprising the overwriting rates for the plurality of blocks, further comprises: maintaining a table comprising a number of accesses and remanence states of the plurality of blocks on the hard disk by the processor;
wherein the assigning the plurality of blocks to the plurality of categories associated with the overwriting rates by the processor further comprises:
defining a space by the processor representing the plurality of blocks with attribute dimensions comprising the number of accesses, time, and the remanence states, and
placing objects representing the plurality of blocks within the space by the processor, and
applying a K-means clustering algorithm on the objects by the processor using a plurality of categories of the attribute dimensions as classes;
wherein the clustering the content of the blocks assigned to the same overwriting rate category in the one or more continuous tracks on the hard disk by the processor further comprises: storing the content of the plurality of blocks in each cluster in the space in the one or more continuous tracks on the hard disk by the processor.
23. The method of claim 19, further comprising:
performing at least one overwrite operation on at least one of the plurality of blocks of a track on the hard disk by the processor;
determining by the processor if a predetermined threshold of overwrites for the block is reached; and
in response to determining that the predetermined threshold of overwrites for the block is reached, refreshing content of adjacent tracks by the processor.
US12/902,150 2010-10-12 2010-10-12 Method and system for mitigating adjacent track erasure in hard disk drives Abandoned US20120089774A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US12/902,150 US20120089774A1 (en) 2010-10-12 2010-10-12 Method and system for mitigating adjacent track erasure in hard disk drives
CN201110304599.4A CN102446511B (en) 2010-10-12 2011-10-10 Method and system for mitigating adjacent track erasure in hard disk drives
TW100136816A TW201229758A (en) 2010-10-12 2011-10-11 Method and system for mitigating adjacent track erasure in hard disk drives
US13/935,119 US8914573B2 (en) 2010-10-12 2013-07-03 Method and system for mitigating adjacent track erasure in hard disk drives

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US12/902,150 US20120089774A1 (en) 2010-10-12 2010-10-12 Method and system for mitigating adjacent track erasure in hard disk drives

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/935,119 Continuation US8914573B2 (en) 2010-10-12 2013-07-03 Method and system for mitigating adjacent track erasure in hard disk drives

Publications (1)

Publication Number Publication Date
US20120089774A1 true US20120089774A1 (en) 2012-04-12

Family

ID=45926015

Family Applications (2)

Application Number Title Priority Date Filing Date
US12/902,150 Abandoned US20120089774A1 (en) 2010-10-12 2010-10-12 Method and system for mitigating adjacent track erasure in hard disk drives
US13/935,119 Expired - Fee Related US8914573B2 (en) 2010-10-12 2013-07-03 Method and system for mitigating adjacent track erasure in hard disk drives

Family Applications After (1)

Application Number Title Priority Date Filing Date
US13/935,119 Expired - Fee Related US8914573B2 (en) 2010-10-12 2013-07-03 Method and system for mitigating adjacent track erasure in hard disk drives

Country Status (3)

Country Link
US (2) US20120089774A1 (en)
CN (1) CN102446511B (en)
TW (1) TW201229758A (en)

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2538825A (en) * 2015-01-21 2016-11-30 HGST Netherlands BV Far field interference mitigation by relative frequency ordering
US10460519B2 (en) * 2013-07-31 2019-10-29 Splunk Inc. Generating cluster states for hierarchical clusters in three-dimensional data models
US10877898B2 (en) 2017-11-16 2020-12-29 Alibaba Group Holding Limited Method and system for enhancing flash translation layer mapping flexibility for performance and lifespan improvements
US10891065B2 (en) 2019-04-01 2021-01-12 Alibaba Group Holding Limited Method and system for online conversion of bad blocks for improvement of performance and longevity in a solid state drive
US10908960B2 (en) 2019-04-16 2021-02-02 Alibaba Group Holding Limited Resource allocation based on comprehensive I/O monitoring in a distributed storage system
US10921992B2 (en) * 2018-06-25 2021-02-16 Alibaba Group Holding Limited Method and system for data placement in a hard disk drive based on access frequency for improved IOPS and utilization efficiency
US10922234B2 (en) 2019-04-11 2021-02-16 Alibaba Group Holding Limited Method and system for online recovery of logical-to-physical mapping table affected by noise sources in a solid state drive
US10970212B2 (en) 2019-02-15 2021-04-06 Alibaba Group Holding Limited Method and system for facilitating a distributed storage system with a total cost of ownership reduction for multiple available zones
US10977122B2 (en) 2018-12-31 2021-04-13 Alibaba Group Holding Limited System and method for facilitating differentiated error correction in high-density flash devices
US10996886B2 (en) 2018-08-02 2021-05-04 Alibaba Group Holding Limited Method and system for facilitating atomicity and latency assurance on variable sized I/O
US11061735B2 (en) 2019-01-02 2021-07-13 Alibaba Group Holding Limited System and method for offloading computation to storage nodes in distributed system
US11061834B2 (en) 2019-02-26 2021-07-13 Alibaba Group Holding Limited Method and system for facilitating an improved storage system by decoupling the controller from the storage medium
US11068409B2 (en) 2018-02-07 2021-07-20 Alibaba Group Holding Limited Method and system for user-space storage I/O stack with user-space flash translation layer
US11074124B2 (en) 2019-07-23 2021-07-27 Alibaba Group Holding Limited Method and system for enhancing throughput of big data analysis in a NAND-based read source storage
US11126561B2 (en) 2019-10-01 2021-09-21 Alibaba Group Holding Limited Method and system for organizing NAND blocks and placing data to facilitate high-throughput for random writes in a solid state drive
US11132291B2 (en) 2019-01-04 2021-09-28 Alibaba Group Holding Limited System and method of FPGA-executed flash translation layer in multiple solid state drives
US11150986B2 (en) 2020-02-26 2021-10-19 Alibaba Group Holding Limited Efficient compaction on log-structured distributed file system using erasure coding for resource consumption reduction
US11169873B2 (en) 2019-05-21 2021-11-09 Alibaba Group Holding Limited Method and system for extending lifespan and enhancing throughput in a high-density solid state drive
US11200114B2 (en) 2020-03-17 2021-12-14 Alibaba Group Holding Limited System and method for facilitating elastic error correction code in memory
US11200337B2 (en) 2019-02-11 2021-12-14 Alibaba Group Holding Limited System and method for user data isolation
US11218165B2 (en) 2020-05-15 2022-01-04 Alibaba Group Holding Limited Memory-mapped two-dimensional error correction code for multi-bit error tolerance in DRAM
US11263132B2 (en) 2020-06-11 2022-03-01 Alibaba Group Holding Limited Method and system for facilitating log-structure data organization
US11281575B2 (en) 2020-05-11 2022-03-22 Alibaba Group Holding Limited Method and system for facilitating data placement and control of physical addresses with multi-queue I/O blocks
US11327929B2 (en) 2018-09-17 2022-05-10 Alibaba Group Holding Limited Method and system for reduced data movement compression using in-storage computing and a customized file system
US11354200B2 (en) 2020-06-17 2022-06-07 Alibaba Group Holding Limited Method and system for facilitating data recovery and version rollback in a storage device
US11354233B2 (en) 2020-07-27 2022-06-07 Alibaba Group Holding Limited Method and system for facilitating fast crash recovery in a storage device
US11372774B2 (en) 2020-08-24 2022-06-28 Alibaba Group Holding Limited Method and system for a solid state drive with on-chip memory integration
US11379127B2 (en) 2019-07-18 2022-07-05 Alibaba Group Holding Limited Method and system for enhancing a distributed storage system by decoupling computation and network tasks
US11379155B2 (en) 2018-05-24 2022-07-05 Alibaba Group Holding Limited System and method for flash storage management using multiple open page stripes
US11385833B2 (en) 2020-04-20 2022-07-12 Alibaba Group Holding Limited Method and system for facilitating a light-weight garbage collection with a reduced utilization of resources
US11416365B2 (en) 2020-12-30 2022-08-16 Alibaba Group Holding Limited Method and system for open NAND block detection and correction in an open-channel SSD
US11422931B2 (en) 2020-06-17 2022-08-23 Alibaba Group Holding Limited Method and system for facilitating a physically isolated storage unit for multi-tenancy virtualization
US11449455B2 (en) 2020-01-15 2022-09-20 Alibaba Group Holding Limited Method and system for facilitating a high-capacity object storage system with configuration agility and mixed deployment flexibility
US11461262B2 (en) 2020-05-13 2022-10-04 Alibaba Group Holding Limited Method and system for facilitating a converged computation and storage node in a distributed storage system
US11461173B1 (en) 2021-04-21 2022-10-04 Alibaba Singapore Holding Private Limited Method and system for facilitating efficient data compression based on error correction code and reorganization of data placement
US11476874B1 (en) 2021-05-14 2022-10-18 Alibaba Singapore Holding Private Limited Method and system for facilitating a storage server with hybrid memory for journaling and data storage
US11487465B2 (en) 2020-12-11 2022-11-01 Alibaba Group Holding Limited Method and system for a local storage engine collaborating with a solid state drive controller
US11494115B2 (en) 2020-05-13 2022-11-08 Alibaba Group Holding Limited System method for facilitating memory media as file storage device based on real-time hashing by performing integrity check with a cyclical redundancy check (CRC)
US11507499B2 (en) 2020-05-19 2022-11-22 Alibaba Group Holding Limited System and method for facilitating mitigation of read/write amplification in data compression
US11556277B2 (en) 2020-05-19 2023-01-17 Alibaba Group Holding Limited System and method for facilitating improved performance in ordering key-value storage with input/output stack simplification
US11617282B2 (en) 2019-10-01 2023-03-28 Alibaba Group Holding Limited System and method for reshaping power budget of cabinet to facilitate improved deployment density of servers
US11726699B2 (en) 2021-03-30 2023-08-15 Alibaba Singapore Holding Private Limited Method and system for facilitating multi-stream sequential read performance improvement with reduced read amplification
US11734115B2 (en) 2020-12-28 2023-08-22 Alibaba Group Holding Limited Method and system for facilitating write latency reduction in a queue depth of one scenario
US11816043B2 (en) 2018-06-25 2023-11-14 Alibaba Group Holding Limited System and method for managing resources of a storage device and quantifying the cost of I/O requests

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9047924B1 (en) * 2014-05-23 2015-06-02 Kabushiki Kaisha Toshiba Magnetic disk device and method of data refresh processing
CN106486140B (en) * 2015-08-27 2019-03-29 株式会社东芝 Disk set and write-in control method
US9390751B1 (en) 2015-10-07 2016-07-12 HGST Netherlands B.V. Reducing overcounting of track-level damage caused by adjacent-track and far-track interference

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5774715A (en) * 1996-03-27 1998-06-30 Sun Microsystems, Inc. File system level compression using holes
US6178058B1 (en) * 1998-12-11 2001-01-23 Iomega Corporation Off-track write protection method and system for induced mechanical disturbance on a disk drive
US6496913B1 (en) * 2000-02-22 2002-12-17 Hewlett-Packard Company System and method for detecting and correcting fragmentation on optical storage media
US20040250029A1 (en) * 2003-06-06 2004-12-09 Minwen Ji Asynchronous data redundancy technique
US20050086651A1 (en) * 2003-10-16 2005-04-21 Yasuhiro Yamamoto Compiler apparatus and linker apparatus
US20090327250A1 (en) * 2006-06-28 2009-12-31 Sun Microsystems, Inc. Method and apparatus for searching and resource discovery in a distributed enterprise system

Family Cites Families (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6202118B1 (en) 1997-09-10 2001-03-13 Micron Technology, Inc. Apparatus for address translation to selectively improve data transfer rates on a disk storage device
US6388833B1 (en) * 1998-06-29 2002-05-14 Western Digital Technologies, Inc. Method for manufacturing a disk drive having an overwriteable clock track
US6400892B1 (en) 1999-01-11 2002-06-04 International Business Machines Corporation Adaptive disk drive operation
US7032119B2 (en) 2000-09-27 2006-04-18 Amphus, Inc. Dynamic power and workload management for multi-server system
JP3971941B2 (en) * 2002-03-05 2007-09-05 三洋電機株式会社 Data storage
JP3829741B2 (en) * 2002-03-19 2006-10-04 ソニー株式会社 Recording medium, recording method, and recording apparatus
KR100468767B1 (en) 2002-09-19 2005-01-29 삼성전자주식회사 Method for preventing adjacent track erase in HDD and apparatus thereof
WO2004053849A1 (en) 2002-12-12 2004-06-24 Fujitsu Limited Disc apparatus, disc apparatus assembly. disc apparatus manufacturing method
US7373268B1 (en) 2003-07-30 2008-05-13 Hewlett-Packard Development Company, L.P. Method and system for dynamically controlling cooling resources in a data center
JP4415610B2 (en) * 2003-08-26 2010-02-17 株式会社日立製作所 System switching method, replica creation method, and disk device
KR100594250B1 (en) * 2004-02-16 2006-06-30 삼성전자주식회사 Method for recording a data in consideration with ATE and recording media in which program therefore are recorded
US7197433B2 (en) 2004-04-09 2007-03-27 Hewlett-Packard Development Company, L.P. Workload placement among data centers based on thermal efficiency
US7447920B2 (en) 2004-08-31 2008-11-04 Hewlett-Packard Development Company, L.P. Workload placement based on thermal considerations
US20060112286A1 (en) 2004-11-23 2006-05-25 Whalley Ian N Method for dynamically reprovisioning applications and other server resources in a computer center in response to power and heat dissipation requirements
JP2006179102A (en) 2004-12-22 2006-07-06 Hitachi Global Storage Technologies Netherlands Bv Magnetic disk apparatus and data recording method
US7325095B2 (en) 2005-02-28 2008-01-29 Hitachi Global Storage Technologies Netherlands B.V. Data storage organization for distributed computing in an intelligent disk drive
US7747907B2 (en) 2005-09-20 2010-06-29 Seagate Technology Llc Preventive recovery from adjacent track interference
JP2008027499A (en) * 2006-07-19 2008-02-07 Lenovo Singapore Pte Ltd Magnetic recording system, magnetic recording method, and magnetic recording program
US7818594B2 (en) 2007-03-21 2010-10-19 Intel Corporation Power efficient resource allocation in data centers
US20090113160A1 (en) 2007-10-25 2009-04-30 Disk Trix Incorporated, A South Carolina Corporation Method and System for Reorganizing a Storage Device
US7738208B2 (en) 2007-11-28 2010-06-15 Samsung Electronics Co., Ltd. Data recovery through eliminating adjacent track interference
US7768729B2 (en) 2008-01-31 2010-08-03 Hitachi Global Storage Technologies Netherlands B.V. Method, system, and computer program product for estimating adjacent track erasure risk by determining erase band width growth rates
US7864476B2 (en) 2008-03-20 2011-01-04 Kabushiki Kaisha Toshiba Low track-per-inch (TPI) zone with reduced need for adjacent-track-erasure (ATE) refresh
US20090244775A1 (en) 2008-03-31 2009-10-01 Kabushiki Kaisha Toshiba 1-1 Adjacent-track-erasure (ate) refresh with increased track resolution for often-written areas
CN101661486B (en) * 2008-08-28 2012-11-07 国际商业机器公司 Method and system for fragment sorting for hard disk of host comprising virtual computer

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5774715A (en) * 1996-03-27 1998-06-30 Sun Microsystems, Inc. File system level compression using holes
US6178058B1 (en) * 1998-12-11 2001-01-23 Iomega Corporation Off-track write protection method and system for induced mechanical disturbance on a disk drive
US6496913B1 (en) * 2000-02-22 2002-12-17 Hewlett-Packard Company System and method for detecting and correcting fragmentation on optical storage media
US20040250029A1 (en) * 2003-06-06 2004-12-09 Minwen Ji Asynchronous data redundancy technique
US20050086651A1 (en) * 2003-10-16 2005-04-21 Yasuhiro Yamamoto Compiler apparatus and linker apparatus
US20090327250A1 (en) * 2006-06-28 2009-12-31 Sun Microsystems, Inc. Method and apparatus for searching and resource discovery in a distributed enterprise system

Cited By (47)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10460519B2 (en) * 2013-07-31 2019-10-29 Splunk Inc. Generating cluster states for hierarchical clusters in three-dimensional data models
US10740970B1 (en) 2013-07-31 2020-08-11 Splunk Inc. Generating cluster states for hierarchical clusters in three-dimensional data models
GB2538825B (en) * 2015-01-21 2017-08-16 HGST Netherlands BV Far field interference mitigation by relative frequency ordering
GB2538825A (en) * 2015-01-21 2016-11-30 HGST Netherlands BV Far field interference mitigation by relative frequency ordering
US10877898B2 (en) 2017-11-16 2020-12-29 Alibaba Group Holding Limited Method and system for enhancing flash translation layer mapping flexibility for performance and lifespan improvements
US11068409B2 (en) 2018-02-07 2021-07-20 Alibaba Group Holding Limited Method and system for user-space storage I/O stack with user-space flash translation layer
US11379155B2 (en) 2018-05-24 2022-07-05 Alibaba Group Holding Limited System and method for flash storage management using multiple open page stripes
US10921992B2 (en) * 2018-06-25 2021-02-16 Alibaba Group Holding Limited Method and system for data placement in a hard disk drive based on access frequency for improved IOPS and utilization efficiency
US11816043B2 (en) 2018-06-25 2023-11-14 Alibaba Group Holding Limited System and method for managing resources of a storage device and quantifying the cost of I/O requests
US10996886B2 (en) 2018-08-02 2021-05-04 Alibaba Group Holding Limited Method and system for facilitating atomicity and latency assurance on variable sized I/O
US11327929B2 (en) 2018-09-17 2022-05-10 Alibaba Group Holding Limited Method and system for reduced data movement compression using in-storage computing and a customized file system
US10977122B2 (en) 2018-12-31 2021-04-13 Alibaba Group Holding Limited System and method for facilitating differentiated error correction in high-density flash devices
US11061735B2 (en) 2019-01-02 2021-07-13 Alibaba Group Holding Limited System and method for offloading computation to storage nodes in distributed system
US11768709B2 (en) 2019-01-02 2023-09-26 Alibaba Group Holding Limited System and method for offloading computation to storage nodes in distributed system
US11132291B2 (en) 2019-01-04 2021-09-28 Alibaba Group Holding Limited System and method of FPGA-executed flash translation layer in multiple solid state drives
US11200337B2 (en) 2019-02-11 2021-12-14 Alibaba Group Holding Limited System and method for user data isolation
US10970212B2 (en) 2019-02-15 2021-04-06 Alibaba Group Holding Limited Method and system for facilitating a distributed storage system with a total cost of ownership reduction for multiple available zones
US11061834B2 (en) 2019-02-26 2021-07-13 Alibaba Group Holding Limited Method and system for facilitating an improved storage system by decoupling the controller from the storage medium
US10891065B2 (en) 2019-04-01 2021-01-12 Alibaba Group Holding Limited Method and system for online conversion of bad blocks for improvement of performance and longevity in a solid state drive
US10922234B2 (en) 2019-04-11 2021-02-16 Alibaba Group Holding Limited Method and system for online recovery of logical-to-physical mapping table affected by noise sources in a solid state drive
US10908960B2 (en) 2019-04-16 2021-02-02 Alibaba Group Holding Limited Resource allocation based on comprehensive I/O monitoring in a distributed storage system
US11169873B2 (en) 2019-05-21 2021-11-09 Alibaba Group Holding Limited Method and system for extending lifespan and enhancing throughput in a high-density solid state drive
US11379127B2 (en) 2019-07-18 2022-07-05 Alibaba Group Holding Limited Method and system for enhancing a distributed storage system by decoupling computation and network tasks
US11074124B2 (en) 2019-07-23 2021-07-27 Alibaba Group Holding Limited Method and system for enhancing throughput of big data analysis in a NAND-based read source storage
US11126561B2 (en) 2019-10-01 2021-09-21 Alibaba Group Holding Limited Method and system for organizing NAND blocks and placing data to facilitate high-throughput for random writes in a solid state drive
US11617282B2 (en) 2019-10-01 2023-03-28 Alibaba Group Holding Limited System and method for reshaping power budget of cabinet to facilitate improved deployment density of servers
US11449455B2 (en) 2020-01-15 2022-09-20 Alibaba Group Holding Limited Method and system for facilitating a high-capacity object storage system with configuration agility and mixed deployment flexibility
US11150986B2 (en) 2020-02-26 2021-10-19 Alibaba Group Holding Limited Efficient compaction on log-structured distributed file system using erasure coding for resource consumption reduction
US11200114B2 (en) 2020-03-17 2021-12-14 Alibaba Group Holding Limited System and method for facilitating elastic error correction code in memory
US11385833B2 (en) 2020-04-20 2022-07-12 Alibaba Group Holding Limited Method and system for facilitating a light-weight garbage collection with a reduced utilization of resources
US11281575B2 (en) 2020-05-11 2022-03-22 Alibaba Group Holding Limited Method and system for facilitating data placement and control of physical addresses with multi-queue I/O blocks
US11494115B2 (en) 2020-05-13 2022-11-08 Alibaba Group Holding Limited System method for facilitating memory media as file storage device based on real-time hashing by performing integrity check with a cyclical redundancy check (CRC)
US11461262B2 (en) 2020-05-13 2022-10-04 Alibaba Group Holding Limited Method and system for facilitating a converged computation and storage node in a distributed storage system
US11218165B2 (en) 2020-05-15 2022-01-04 Alibaba Group Holding Limited Memory-mapped two-dimensional error correction code for multi-bit error tolerance in DRAM
US11507499B2 (en) 2020-05-19 2022-11-22 Alibaba Group Holding Limited System and method for facilitating mitigation of read/write amplification in data compression
US11556277B2 (en) 2020-05-19 2023-01-17 Alibaba Group Holding Limited System and method for facilitating improved performance in ordering key-value storage with input/output stack simplification
US11263132B2 (en) 2020-06-11 2022-03-01 Alibaba Group Holding Limited Method and system for facilitating log-structure data organization
US11354200B2 (en) 2020-06-17 2022-06-07 Alibaba Group Holding Limited Method and system for facilitating data recovery and version rollback in a storage device
US11422931B2 (en) 2020-06-17 2022-08-23 Alibaba Group Holding Limited Method and system for facilitating a physically isolated storage unit for multi-tenancy virtualization
US11354233B2 (en) 2020-07-27 2022-06-07 Alibaba Group Holding Limited Method and system for facilitating fast crash recovery in a storage device
US11372774B2 (en) 2020-08-24 2022-06-28 Alibaba Group Holding Limited Method and system for a solid state drive with on-chip memory integration
US11487465B2 (en) 2020-12-11 2022-11-01 Alibaba Group Holding Limited Method and system for a local storage engine collaborating with a solid state drive controller
US11734115B2 (en) 2020-12-28 2023-08-22 Alibaba Group Holding Limited Method and system for facilitating write latency reduction in a queue depth of one scenario
US11416365B2 (en) 2020-12-30 2022-08-16 Alibaba Group Holding Limited Method and system for open NAND block detection and correction in an open-channel SSD
US11726699B2 (en) 2021-03-30 2023-08-15 Alibaba Singapore Holding Private Limited Method and system for facilitating multi-stream sequential read performance improvement with reduced read amplification
US11461173B1 (en) 2021-04-21 2022-10-04 Alibaba Singapore Holding Private Limited Method and system for facilitating efficient data compression based on error correction code and reorganization of data placement
US11476874B1 (en) 2021-05-14 2022-10-18 Alibaba Singapore Holding Private Limited Method and system for facilitating a storage server with hybrid memory for journaling and data storage

Also Published As

Publication number Publication date
CN102446511B (en) 2014-09-17
CN102446511A (en) 2012-05-09
US20130293980A1 (en) 2013-11-07
US8914573B2 (en) 2014-12-16
TW201229758A (en) 2012-07-16

Similar Documents

Publication Publication Date Title
US8914573B2 (en) Method and system for mitigating adjacent track erasure in hard disk drives
US10318181B2 (en) System, method, and computer program product for increasing spare space in memory to extend a lifetime of the memory
US9612953B1 (en) Data placement based on data properties in a tiered storage device system
US9811457B2 (en) Data placement based on data retention in a tiered storage device system
US9696916B2 (en) Techniques for reducing memory write operations using coalescing memory buffers and difference information
US7809900B2 (en) System, method, and computer program product for delaying an operation that reduces a lifetime of memory
US8230164B2 (en) Techniques for multi-memory device lifetime management
US7904764B2 (en) Memory lifetime gauging system, method and computer program product
US8825980B2 (en) Consideration of adjacent track interference and wide area adjacent track erasure during disk defragmentation
JP2013509658A (en) Allocation of storage memory based on future usage estimates
US10541004B2 (en) Shortening the average reposition time to the beginning of files in a magnetic tape
US20080126685A1 (en) System, method, and computer program product for reducing memory write operations using an instruction set
KR20170023734A (en) Methods and systems for improving flash memory flushing
US20140281281A1 (en) Host command based read disturb methodology
CN104461384B (en) A kind of method for writing data and storage device
CN106020717B (en) Data processing method and electronic equipment
US9891824B2 (en) Sub-block input/output (I/O) commands for storage device including byte stream buffer
US9009430B2 (en) Restoration of data from a backup storage volume
US10482012B1 (en) Storage system and method of operating thereof
CN104252415B (en) Method and system for redistributing data
US8656066B2 (en) Monitoring input/output operations to specific storage locations
US8930646B2 (en) Characterization and optimization of tracks on disks
US9858179B2 (en) Data sort using memory-intensive exosort
WO2015109128A1 (en) Data replacement based on data properties and data retention in a tiered storage device system
KR101669722B1 (en) Database management apparatus and method

Legal Events

Date Code Title Description
AS Assignment

Owner name: INTERNATIONAL BUSINESS MACHINES CORPORATION, NEW Y

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KELKAR, BHOOSHAN P.;NAGPAL, ABHINAY R.;PATIL, SANDEEP R.;SIGNING DATES FROM 20100927 TO 20100928;REEL/FRAME:025121/0607

AS Assignment

Owner name: INTERNATIONAL BUSINESS MACHINES CORPORATION, NEW Y

Free format text: CORRECTIVE ASSIGNMENT TO CORRECT THE ADDRESS OF ASSIGNEE PREVIOUSLY RECORDED ON REEL 025121 FRAME 0607. ASSIGNOR(S) HEREBY CONFIRMS THE NEW ORCHARD ROAD;ASSIGNORS:KELKAR, BHOOSHAN P.;NAGPAL, ABHINAY R.;PATIL, SANDEEP R.;SIGNING DATES FROM 20100927 TO 20100928;REEL/FRAME:025239/0830

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE