Wear leveling of solid state disks based on usage information of data and parity received from a raid controller

• US 8,234,520 B2
• Filed: 09/16/2009
• Issued: 07/31/2012
• Est. Priority Date: 09/16/2009
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Walls, Andrew Dale, Moertl, Daniel Frank
• Primary Examiner(s): SCHELL, JOSEPH O
• Application Number:
  US12/561,210
• Publication Number:
  US 20110066882A1
• Time in Patent Office: 1,049 Days
• Field of Search: 714/6, 714/47, 714/6.1, 714/6.2, 714/6.21, 714/6.22, 714/47.1, 714/47.2, 714/47.3, 711/114
• US Class Current: 714/6.22
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2211/1057 Parity-multiple bits-RAID6, i.e. RAID 6 implementations
• CPC Class Codes: G06F 2211/1088 Scrubbing in RAID systems with parity
• CPC Class Codes: G06F 2212/7208 Multiple device management, e.g. distributing data over multiple flash devices
• CPC Class Codes: G06F 2212/7211 Wear leveling
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles

Abstract

A controller configures a plurality of solid state disks as a redundant array of independent disks (RAID), wherein the plurality of solid state disks store a plurality of blocks, and wherein storage areas of the plurality of solid state disks corresponding to at least some blocks of the plurality of blocks have different amounts of estimated life expectancies. The controller includes in data structures associated with a block that is to be stored in the storage areas of the plurality of solid state disks an indication that the block includes parity information corresponding to the RAID, wherein parity information comprises information corresponding to an error correction mechanism to protect against a disk failure. The controller sends the data structures to the plurality of solid state disks, wherein the plurality of solid state disks allocate a storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas to store the block that includes the parity information.

Claims

1. A method, comprising:

configuring, by a controller, a plurality of solid state disks as a redundant array of independent disks (RAID), wherein the plurality of solid state disks store a plurality of blocks, and wherein storage areas of the plurality of solid state disks corresponding to at least some blocks of the plurality of blocks have different amounts of estimated life expectancies;

including, by the controller, in data structures associated with a block that is to be stored in the storage areas of the plurality of solid state disks, an indication that the block includes parity information corresponding to the RAID, wherein parity information comprises information corresponding to an error correction mechanism to protect against a disk failure; and

sending, by the controller, the data structures to the plurality of solid state disks, wherein the plurality of solid state disks allocate a storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas to store the block that includes the parity information, wherein the block is a first block and the data structures are first data structures, wherein second data structures associated with a second block contain an indication of how many data drives are present in the RAID, and wherein the second block is stored in an area of greater life expectancy than a third block in response to determining that the second block is for a greater number of data drives than the third block.

2. The method of claim 1, wherein the first and the second data structures are included in a Small Computer Systems Interface (SCSI) command descriptor block (CDB), and wherein unused bits of the CDB are used to store the first and the second data structures.

3. The method of claim 1 wherein the first and the second data structures are included in configuration registers of a Peripheral Component Interconnect (PCI) compliant card.

4. The method of claim 1, wherein the storage area is a first storage area, wherein the indication is a first indication, the method further comprising:

including, by the controller, in the second data structures associated with the second block that is to be stored in the storage areas of the solid state disks a second indication, wherein the second indication indicates a relative frequency with which the data stored in the second block is likely to be updated, wherein a second storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas is used to store the second block, wherein the second block has a higher relative frequency of updates in comparison to other blocks.

5. A controller in communication with a plurality of solid state disks, the controller comprising:

a memory; and

a processor coupled to the memory, wherein the processor performs operations, the operations comprising;

configuring a plurality of solid state disks as a redundant array of independent disks (RAID), wherein the plurality of solid state disks store a plurality of blocks, and wherein storage areas of the plurality of solid state disks corresponding to at least some blocks of the plurality of blocks have different amounts of estimated life expectancies;

including in data structures associated with a block that is to be stored in the storage areas of the plurality of solid state disks, an indication that the block includes parity information corresponding to the RAID, wherein parity information comprises information corresponding to an error correction mechanism to protect against a disk failure; and

sending the data structures to the plurality of solid state disks, wherein the plurality of solid state disks allocate a storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas to store the block that includes the parity information, wherein the block is a first block and the data structures are first data structures, wherein second data structures associated with a second block contain an indication of how many data drives are present in the RAID, and wherein the second block is stored in an area of greater life expectancy than a third block in response to determining that the second block is for a greater number of data drives than the third block.

6. The controller of claim 5, wherein the first and the second data structures are included in a Small Computer Systems Interface (SCSI) command descriptor block (CDB), and wherein unused bits of the CDB are used to store the first and the second data structures.

7. The controller of claim 5, wherein the first and the second data structures are included in configuration registers of a Peripheral Component Interconnect (PCI) compliant card.

8. The controller of claim 5, wherein the storage area is a first storage area, wherein the indication is a first indication, the operations further comprising:

including, by the controller, in the second data structures associated with the second block that is to be stored in the storage areas of the solid state disks a second indication, wherein the second indication indicates a relative frequency with which the data stored in the second block is likely to be updated, wherein a second storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas is used to store the second block, wherein the second block has a higher relative frequency of updates in comparison to other blocks.

9. A computer program product for wear leveling of a plurality of solid state disks, the computer program product comprising:

a computer readable storage medium comprising at least one of a memory, a magnetic disk, and an optical disc, the computer readable storage medium having computer readable program code embodied therewith, the computer readable program code configured to;

configure a plurality of solid state disks as a redundant array of independent disks (RAID), wherein the plurality of solid state disks store a plurality of blocks, and wherein storage areas of the plurality of solid state disks corresponding to at least some blocks of the plurality of blocks have different amounts of estimated life expectancies;

include in data structures associated with a block that is to be stored in the storage areas of the plurality of solid state disks, an indication that the block includes parity information corresponding to the RAID, wherein parity information comprises information corresponding to an error correction mechanism to protect against a disk failure; and

send the data structures to the plurality of solid state disks, wherein the plurality of solid state disks allocate a storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas to store the block that includes the parity information, wherein the block is a first block and the data structures are first data structures, wherein second data structures associated with a second block contain an indication of how many data drives are present in the RAID, and wherein the second block is stored in an area of greater life expectancy than a third block in response to determining that the second block is for a greater number of data drives than the third block.

10. The computer program product of claim 9, wherein the first and the second data structures are included in a Small Computer Systems Interface (SCSI) command descriptor block (CDB), and wherein unused bits of the CDB are used to store the first and the second data structures.

11. The computer program product of claim 9, wherein the first and the second data structures are included in configuration registers of a Peripheral Component Interconnect (PCI) compliant card.

12. The computer program product of claim 9, wherein the storage area is a first storage area, wherein the indication is a first indication, the computer readable program code further configured to:

include in the second data structures associated with the second block that is to be stored in the storage areas of the solid state disks a second indication, wherein the second indication indicates a relative frequency with which the data stored in the second block is likely to be updated, wherein a second storage area that is estimated to have a relatively greater life expectancy in comparison to other storage areas is used to store the second block, wherein the second block has a higher relative frequency of updates in comparison to other blocks.