Shifting wearout of storage disks

• US 10,664,176 B2
• Filed: 04/16/2018
• Issued: 05/26/2020
• Est. Priority Date: 10/22/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Franke, Jeffery M., O'Connor, James A.
• Primary Examiner(s): Wong, Nanci N
• Application Number:
  US15/953,713
• Publication Number:
  US 20180232161A1
• Time in Patent Office: 771 Days
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/16 Error detection or correction of the data by redundancy in hardware
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: G06F 2213/0024 Peripheral component interconnect [PCI]
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Technical solutions are described for shifting wearout of an array of storage disks in a storage system. In an aspect, a method includes staggering completion of maximum number of writes for each storage disk in the array. The method also includes copying data from a storage disk in the array to a replacement disk and redirecting a request to access the data from the storage disk to the replacement disk. The method also includes, in response to passage of a predetermined duration of time since copying the data from the storage disk to the replacement disk, copying the data from the replacement disk to the storage disk and directing the request to access the data from the storage disk back to the storage disk.

Claims

1. A method for shifting wearout of storage disks in an array of storage disks in a storage system, the method comprising:

determining, by a controller of the storage system, a first replacement duration for the array, the first replacement duration is determined based on a mean time to failure of the storage disks in the array, the replacement duration being a sum of the mean time to failure and a predetermined deviation of the mean time to failure;

replacing, by the controller, for the first replacement duration, a first pair of storage disks with a pair of replacement disks, the first pair of storage disks comprising a first storage disk and a second storage disk, and the pair of replacement disks comprising a first replacement disk and a second replacement disk, the first storage disk replaced by the first replacement disk and the second storage disk replaced by the second replacement disk, and wherein replacing a storage disk by a replacement disk comprises;

copying, by the controller data from the storage disk in the array to the replacement disk; and

redirecting, by the controller, a request to access the data from the storage disk to the replacement disk;

determining, by the controller, a second replacement duration for the array, the second replacement duration is a multiple of the first replacement duration; and

replacing, by the controller, a second pair of storage disks with the pair of replacement disks for the second replacement duration.

2. The method of claim 1, further comprising, in response to passage of the first replacement duration, copying, by the controller, the data from the pair of replacement disks to the first pair of storage disks and directing the request to access the data from the first pair of storage disks back to the first pair of storage disks.

3. The method of claim 2, further comprising, in response to passage of the second replacement duration, copying, by the controller, the data from the pair of replacement disks back to the second pair of storage disks and directing the request to access the data from the second pair of storage disks back to the second pair of storage disks.

4. The method of claim 1, wherein the data from the first storage disk is copied to the first replacement disk in parallel to copying the data from the second storage disk to the second replacement disk.

5. The method of claim 1, wherein a storage disk in the array is one of a solid state drive, a flash memory, or a flash dual in-line memory module (DIMM), interfaced using a peripheral component interconnect (PCI) card or a serial attached small computer system interface (SAS).

6. The method of claim 5, wherein the array of storage disks is maintained as a redundant array of independent disks (RAID).

7. A storage system comprising:

a plurality of storage disks in an array; and

a controller that stores data across the storage disks, wherein the controller is configured to stagger completion of maximum number of writes for each storage disk in the array, the controller being configured to perform the staggering comprising;

determining a first replacement duration for the array, the first replacement duration is determined based on a mean time to failure of the storage disks in the array, the replacement duration being a sum of the mean time to failure and a predetermined deviation of the mean time to failure;

replacing for the first replacement duration, a first pair of storage disks with a pair of replacement disks, the first pair of storage disks comprising a first storage disk and a second storage disk, and the pair of replacement disks comprising a first replacement disk and a second replacement disk, the first storage disk replaced by the first replacement disk and the second storage disk replaced by the second replacement disk, and wherein replacing a storage disk by a replacement disk comprises;

copying data from the storage disk in the array to the replacement disk; and

redirecting a request to access the data from the storage disk to the replacement disk;

determining a second replacement duration for the array, the second replacement duration is a multiple of the first replacement duration; and

replacing a second pair of storage disks with the pair of replacement disks for the second replacement duration.

8. The storage system of claim 7, wherein performing the staggering further comprises:

in response to passage of the first replacement duration, copying, by the controller, the data from the pair of replacement disks to the first pair of storage disks and directing the request to access the data from the first pair of storage disks back to the first pair of storage disks.

9. The storage system of claim 8, wherein performing the staggering further comprises:

in response to passage of the second replacement duration, copying, by the controller, the data from the pair of replacement disks back to the second pair of storage disks and directing the request to access the data from the second pair of storage disks back to the second pair of storage disks.

10. The storage system of claim 7, wherein the data from the first storage disk is copied to the first replacement disk in parallel to copying the data from the second storage disk to the second replacement disk.

11. The storage system of claim 7, wherein a storage disk in the array is one of a solid state drive, a flash memory, or a flash dual in-line memory module (DIMM), interfaced using a peripheral component interconnect (PCI) card or a serial attached small computer system interface (SAS).

12. The storage system of claim 11, wherein the array of storage disks is maintained as a redundant array of independent disks (RAID).

13. A computer program product for controlling read-write operations of storage disks arranged in an array, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a controller to cause the controller to stagger wearout of the storage disks, the staggering comprising:

determining a first replacement duration for the array, the first replacement duration is determined based on a mean time to failure of the storage disks in the array, the replacement duration being a sum of the mean time to failure and a predetermined deviation of the mean time to failure;

replacing for the first replacement duration, a first pair of storage disks with a pair of replacement disks, the first pair of storage disks comprising a first storage disk and a second storage disk, and the pair of replacement disks comprising a first replacement disk and a second replacement disk, the first storage disk replaced by the first replacement disk and the second storage disk replaced by the second replacement disk, and wherein replacing a storage disk by a replacement disk comprises;

copying data from the storage disk in the array to the replacement disk; and

redirecting a request to access the data from the storage disk to the replacement disk;

determining a second replacement duration for the array, the second replacement duration is a multiple of the first replacement duration; and

replacing a second pair of storage disks with the pair of replacement disks for the second replacement duration.

14. The computer product of claim 13, wherein performing the staggering further comprises:

in response to passage of the first replacement duration, copying, by the controller, the data from the pair of replacement disks to the first pair of storage disks and directing the request to access the data from the first pair of storage disks back to the first pair of storage disks.

15. The computer product of claim 14, wherein performing the staggering further comprises:

in response to passage of the second replacement duration, copying, by the controller, the data from the pair of replacement disks back to the second pair of storage disks and directing the request to access the data from the second pair of storage disks back to the second pair of storage disks.

16. The computer product of claim 13, wherein the data from the first storage disk is copied to the first replacement disk in parallel to copying the data from the second storage disk to the second replacement disk.

17. The computer product of claim 13, wherein a storage disk in the array is one of a solid state drive, a flash memory, or a flash dual in-line memory module (DIMM), interfaced using a peripheral component interconnect (PCI) card or a serial attached small computer system interface (SAS).