ENHANCED DATA RECOVERY FROM DATA STORAGE DEVICES

• US 20150082084A1
• Filed: 09/16/2013
• Published: 03/19/2015
• Est. Priority Date: 09/16/2013
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: HGST Netherlands B.V. (Western Digital Corporation)
• Inventors: Guyot, Cyril, Bandic, Zvonimir
• Granted Patent: US 9,323,630 B2
• Time in Patent Office: Days
• US Class Current: 714/15
• CPC Class Codes: G06F 11/073 in a memory management context, e.g. virtual memory or cache management memory management G06F12/00; testing of static memory units G11C29/00
• 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

Abstract

Systems, methods, and firmware for recovery of data from storage devices are provided herein. In one example, a data storage device is provided. The data storage device includes a storage portion and a cache portion which caches data intended for storage in the storage portion. Responsive to a recovery read command identifying requested data, the data storage device retrieves stored data corresponding to the requested data from the storage portion without retrieving cached data corresponding to the requested data from the cache portion that supersedes at least a portion of the stored data. Responsive to a cache block list command, the data storage device transfers a list identifying one or more cached blocks of the cached data. Responsive to a read command that identifies at least one cached block, the data storage device retrieves the at least one cached block.

Claims

1. A data storage device, comprising:

a storage medium comprising a storage portion and a cache portion, wherein the cache portion caches data for storage in the storage portion; and

a storage controller configured to;

responsive to a recovery read command identifying requested data, retrieve stored data corresponding to the requested data from the storage portion without retrieving cached data corresponding to the requested data from the cache portion that supersedes at least a portion of the stored data;

responsive to a cache block list command, transfer a list identifying one or more blocks of the cached data; and

responsive to a read command that identifies at least one cached block of the cached data, retrieve the at least one cached block of the cached data from the cache portion.

2. The data storage device of claim 1, wherein the requested data corresponds to data that is included in both the storage portion and the cache portion, and wherein the cached data comprises pending data which supersedes corresponding stale portions of the stored data included in the storage portion.

3. The data storage device of claim 1, wherein the recovery read command is only active when the data storage device is instructed to first enter into a recovery mode.

4. The data storage device of claim 1, wherein the list identifying the one or more blocks of the cached data identifies one or more logical block addresses (LBAs) corresponding to the one or more blocks of the cached data.

5. The data storage device of claim 1, wherein the recovery read command comprises a read command for retrieving the requested data on the data storage device identified by one or more logical block addresses (LBAs).

6. The data storage device of claim 1, comprising:

the storage controller further configured to;

responsive to an instruction to enter into a recovery mode, inhibit the cached data from transfer into the storage portion and inhibit incoming write data from storage in the data storage device.

7. The data storage device of claim 1, wherein the storage portion comprises a shingled magnetic recording (SMR) arrangement and the cache portion comprises a non-SMR arrangement.

8. The data storage device of claim 1, comprising:

the storage controller further configured to;

responsive to an instruction to exit the recovery mode, allow the read command to retrieve the at least one cached block of the cached data, wherein the data storage device responds to the read command while in the recovery mode by retrieving data associated with the read command from the storage portion and not from the cache portion.

9. The data storage device of claim 1, comprising:

the storage controller further configured to;

responsive to retrieving the stored data, transfer the stored data as portions of the requested data for storage on another data storage device, wherein other portions of the requested data corresponding to the cached data are transferred as zeroed out data; and

responsive to retrieving the at least one cached block of the cached data, transfer the at least one cached block of the cached data for storage on the other data storage device.

10. A method of operating a data storage device that includes a storage portion and a cache portion which caches data intended for storage in the storage portion, the method comprising:

responsive to a recovery read command identifying requested data, retrieving stored data corresponding to the requested data from the storage portion without retrieving cached data corresponding to the requested data from the cache portion that supersedes at least a portion of the stored data;

responsive to a cache block list command, transferring a list identifying one or more cached blocks of the cached data; and

responsive to a read command that identifies at least one cached block, retrieving the at least one cached block.

11. The method of claim 10, wherein the requested data corresponds to data that is included in both the storage portion and the cache portion, and wherein the cached data comprises pending data which supersedes corresponding stale portions of the stored data included in the storage portion.

12. The method of claim 10, wherein the recovery read command is only active when the data storage device is instructed to first enter into a recovery mode.

13. The method of claim 10, wherein the list identifying the one or more blocks of the cached data identifies one or more logical block addresses (LBAs) corresponding to the one or more blocks of the cached data.

14. The method of claim 10, wherein the recovery read command comprises a read command for retrieving the requested data on the data storage device identified by one or more logical block addresses (LBAs).

15. The method of claim 10, further comprising:

responsive to an instruction to enter into a recovery mode, inhibiting the cached data from transfer into the storage portion and inhibiting incoming write data from storage in the data storage device.

16. The method of claim 10, wherein the storage portion comprises a shingled magnetic recording (SMR) arrangement and the cache portion comprises a non-SMR arrangement.

17. The method of claim 10, further comprising:

responsive to an instruction to exit the recovery mode, allowing the read command to retrieve the at least one cached block of the cached data, wherein the data storage device responds to the read command while in the recovery mode by retrieving data associated with the read command from the storage portion and not from the cache portion.

18. The method of claim 10, further comprising:

responsive to retrieving the stored data, transferring the stored data as portions of the requested data for storage on another data storage device, wherein other portions of the requested data corresponding to the cached data are transferred as zeroed out data; and

responsive to retrieving the at least one cached block of the cached data, transferring the at least one cached block of the cached data for storage on the other data storage device.

19. A data storage system that includes an origin storage device and a target storage device, the data storage system comprising:

a host system configured to issue a recovery read command to the origin storage device for requested data;

responsive to the recovery read command, the origin storage device configured to responsively retrieve stored portions of the requested data that are included in a storage portion of the origin storage device and not retrieve cached portions of the requested data that are included in a cache portion of the origin storage device, the requested data corresponding to data included in both the storage portion and the cache portion;

responsive to retrieving the stored portions of the requested data, the origin storage device configured to transfer the stored portions as the requested data without the cached portions of the requested data;

the host system configured to request a list identifying the cached portions from the origin storage device and responsively receive the list identifying the cached portions;

the host system configured to issue a read command to the origin storage device to retrieve at least one of the cached potions;

responsive to retrieving the at least one of the cached portions, the origin storage device configured to transfer the at least one of the cached portions.

20. The method of claim 19, comprising:

the origin storage device configured to transfer the requested data with zeroed out portions that correspond to the cached portions of the requested data.