System and method for replacing storage devices

• US 10,007,432 B2
• Filed: 10/13/2015
• Issued: 06/26/2018
• Est. Priority Date: 10/13/2015
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Atluri, Anup, Vellimalai, Ashokan, Singh, Amit Pratap, Agarwal, Sandeep, Sreedhar M, Deepu Syam
• Primary Examiner(s): Rojas, Midys
• Assistant Examiner(s): Doan, Khoa D
• Application Number:
  US14/882,409
• Publication Number:
  US 20170102883A1
• Time in Patent Office: 987 Days
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2094 Redundant storage or storage space G06F11/2056 takes precedence
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A method for copying data from a storage device that has been identified for replacement or has failed to a spare storage device. The method includes a storage controller tracking input/output statistics for several storage devices. The storage controller determines if a first storage device storing first data has been identified for replacement within the storage devices. In response to the first storage device having been identified for replacement, a first least written to data address space within the first storage device is determined based on the input/output statistics. First data contained in the first least written to data address space is copied from the first storage device to the spare storage device.

Claims

1. A method of operating a redundant array of independent drives (RAID) storage system having a plurality of storage devices and a spare storage device, the method comprising:

a storage controller tracking input/output statistics for the storage devices;

determining that a first storage device storing data has been identified for replacement within the plurality of storage devices;

in response to the first storage device having been identified for replacement;

sorting a list of data address spaces for the first storage device from a lowest frequency access to a highest frequency access, based on the I/O statistics for each data address space;

determining a least written to data address space within the first storage device based on the input/output statistics; and

copying data from the first storage device to the spare storage device in sequential order beginning with copying first data contained in a least written to data address space having lowest frequency access to data contained in a data address space having highest frequency access.

2. The method of claim 1, further comprising:

determining if all of the data contained on the first storage device has been copied to the spare storage device;

when all of the data contained on the first storage device has not been copied to the spare storage device, determining a next least written to data address space within the first storage device based on the input/output statistics; and

copying second data contained in the next least written to data address space from the first storage device to the spare storage device.

3. The method of claim 2, further comprising:

marking the data address spaces that have been copied to the spare storage device as data address spaces that have been copied.

4. The method of claim 1, wherein the storage controller tracking input/output statistics for the storage devices further comprises:

generating a list of data address spaces for each active storage device;

tracking within the list of data address spaces, an associated frequency of access for each of the data access spaces; and

automatically updating the associated frequency of access for each of the data access spaces whenever the data address space is written to and/or read from.

5. The method of claim 4, further comprising:

sorting the list of data address spaces for the first storage device based on the frequency of write operations, from the lowest frequency to the highest frequency.

6. The method of claim 1, further comprising:

preventing writes to the least written to data address space on the first storage device when the first data is being copied from the first storage device to the spare storage device.

7. The method of claim 1, wherein the storage controller initializes the RAID storage system, the initialization comprising:

generating a plurality of disk groups in the storage devices;

dividing the disk groups into a plurality of data address spaces; and

generating a list of data address spaces for each disk group to track a frequency of write and read operations to each data address space.

8. The method of claim 1, further comprising:

performing a consistency check operation on the copied data on the spare storage device;

determining if the consistency check has passed; and

in response to the consistency check not passing, re-copying the first data from the first storage device to the spare storage device, wherein the performing, determining, and re-copying is performed one or more times up to a pre-set threshold number of times greater than zero.

9. A redundant array of independent drives (RAID) storage system comprising:

a plurality of storage devices including a spare storage device;

a storage controller coupled to the plurality of storage devices for controlling storage operations, wherein the storage controller comprises logic that;

tracks input/output statistics for the storage devices;

determines if a first storage device storing data has been identified for replacement within the storage devices; and

in response to the first storage device having been identified for replacement;

sorts a list of data address spaces for the first storage device from a lowest frequency access to a highest frequency access, based on the I/O statistics for each data address space;

determines a least written to data address space within the first storage device based on the input/output statistics; and

copies the data within the data address spaces for the first storage device from the first storage device to the replacement storage device in sequential order from a data address space having lowest frequency access to a data address space having highest frequency of access, wherein the logic first copies first data contained in the least written to data address space from the first storage device to the spare storage device.

10. The storage system of claim 9, wherein the storage controller further comprises logic that:

determines if all of the data contained on the first storage device has been copied to the spare storage device;

when all of the data contained on the first storage device has not been copied to the spare storage device, determines a next least written to data address space within the first storage device based on the input/output statistics; and

copies second data contained in the next least written to data address space from the first storage device to the spare storage device.

11. The storage system of claim 10, wherein the storage controller further comprises logic that:

marks the data address spaces that have been copied to the spare storage device as data address spaces that have been copied.

12. The storage system of claim 9, wherein the storage controller further comprises logic that:

generates a list of data address spaces for each active storage device;

tracks within the list of data address spaces, an associated frequency of access for each of the data access spaces; and

automatically updates the associated frequency of access for each of the data access spaces whenever the data address space is written to and/or read from.

13. The storage system of claim 12, wherein the storage controller further comprises logic that:

sorts the list of data address spaces for the first storage device based on the frequency of write operations, from the lowest frequency to the highest frequency.

14. The storage system of claim 9, wherein the storage controller further comprises logic that:

prevents writes to the least written to data address space on the first storage device when the first data is being copied from the first storage device to the spare storage device.

15. The storage system of claim 9, wherein the RAID storage system is initialized by the storage controller further comprising logic that:

generates a plurality of disk groups in the storage devices;

divides the disk groups into a plurality of data address spaces; and

generates a list of data address spaces for each disk group to track a frequency of write and read operations to each data address space.

16. The storage system of claim 9 wherein the storage controller further comprises logic that:

performs a consistency check operation on the copied data on the spare storage device;

determines if the consistency check has passed; and

in response to the consistency check not passing, re-copies the first data from the first storage device to the spare storage device, wherein the performing, determining, and re-copying is performed one or more times up to a pre-set threshold number of times greater than zero.

17. An information handling system comprising:

one or more processors;

a storage system in communication with the one or more processors, the storage system comprising;

a plurality of storage devices including a spare storage device; and

a storage controller coupled to the plurality of storage devices, the storage controller having firmware executing thereon to provide control of storage system operations, wherein the firmware configures the storage controller to;

track input/output statistics for the storage devices;

determine if a first storage device storing data has been identified for replacement within the storage devices;

in response to the first storage device having been identified for replacement;

sort a list of data address spaces for the first storage device from a lowest frequency access to a highest frequency access, based on the I/O statistics for each data address space;

determine a least written to data address space within the first storage device based on the input/output statistics; and

copy the data within the data address spaces for the first storage device from the first storage device to the replacement storage device in sequential order from a data address space having lowest frequency access to a data address space having highest frequency of access, wherein the controller first copies first data contained in the least written to data address space from the first storage device to the spare storage device.

18. The information handling system of claim 17, wherein the firmware further configures the storage controller to:

determine if all of the data contained on the first storage device has been copied to the spare storage device;

when all of the data contained on the first storage device has not been copied to the spare storage device, determine a next least written to data address space within the first storage device based on the input/output statistics; and

copy second data contained in the next least written to data address space from the first storage device to the spare storage device.

19. The information handling system of claim 18, wherein the firmware further configures the storage controller to:

mark the data address spaces that have been copied to the spare storage device as data address spaces that have been copied.

20. The information handling system of claim 17, wherein the firmware further configures the storage controller to:

generate a list of data address spaces for each active storage device;

track within the list of data address spaces, an associated frequency of access for each of the data access spaces; and

automatically update the associated frequency of access for each of the data access spaces whenever the data address space is written to and/or read from.

21. The information handling system of claim 20, wherein the firmware further configures the storage controller to:

sort the list of data address spaces for the first storage device based on the frequency of write operations, from the lowest frequency to the highest frequency.

22. The information handling system of claim 17, wherein the firmware further configures the storage controller to:

prevent writes to the least written to data address space on the first storage device when the first data is being copied from the first storage device to the spare storage device.

23. The information handling system of claim 17, wherein the RAID storage system is initialized by the firmware further configuring the storage controller to:

generate a plurality of disk groups in the storage devices;

divide the disk groups into a plurality of data address spaces; and

generate a list of data address spaces for each disk group to track a frequency of write and read operations to each data address space.

24. The information handling system of claim 17, wherein the firmware further configures the storage controller to:

perform a consistency check operation on the copied data on the spare storage device;

determine if the consistency check has passed; and

in response to the consistency check not passing, re-copy the first data from the first storage device to the spare storage device, wherein the performing, determining, and re-copying is performed one or more times up to a pre-set threshold number of times greater than zero.