INFORMATION HANDLING SYSTEM INCLUDING A LOGICAL VOLUME AND A CACHE AND A METHOD OF USING THE SAME

• US 20090125676A1
• Filed: 11/14/2007
• Published: 05/14/2009
• Est. Priority Date: 11/14/2007
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Cherian, Jacob, Vinante, Marcelo D., Huang, Douglas
• Granted Patent: US 7,797,501 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system and method of recovering cached data can be used when a particular physical storage device becomes unsuitable for storing data. In one aspect, the method can include providing the information handling system including a logical volume and a cache. The cache includes data that is to be stored within a particular physical storage device. The method can also include persisting the data within a different physical storage device. In one embodiment, the different physical storage device can be used to temporarily store the data when a logical volume is inaccessible. After the particular physical storage device becomes suitable to persist the data, the logical volume can be restored. The method can further include persisting the data within the particular or a replacement physical storage device. In another aspect, a system can be configured to carry out the methods described herein.

Claims

1. A method of storing data within an information handling system comprising:

providing the information handling system including a logical volume and a cache, wherein the logical volume includes a first physical storage device and a second physical storage device, and the cache includes actual data that is to be persisted within the first physical storage device;

persisting the actual data within the second physical storage device that is different from the first physical storage device; and

persisting the actual data within a third physical storage device after persisting the actual data within the second physical storage device, wherein the third physical storage device is part of the logical volume and is different from the second physical storage device.

2. The method of claim 1, wherein the first physical storage device and the third physical storage device are a same physical storage device.

3. The method of claim 1, wherein the first physical storage device and the third physical storage device are different physical storage devices.

4. The method of claim 1, further comprising:

determining that the logical volume is inaccessible before persisting the actual data within the second physical storage device;

determining that the logical volume is accessible after persisting the actual data within the second physical storage device; and

restoring the actual data to the cache after persisting the actual data within the second physical storage device and before persisting the actual data within the third physical storage device.

5. The method of claim 4, further comprising restoring access to a host system.

6. The method of claim 1, wherein persisting the actual data within the second physical storage device comprises persisting the actual data within a reserved portion of the second physical storage device, wherein the reserved portion is not used for persisting actual data when the logical volume is accessible.

7. The method of claim 6, wherein the reserved portion of the second physical storage device comprises a metadata portion of the second physical storage device.

8. The method of claim 7, further comprising persisting the actual data within other metadata portions of other physical storage devices.

9. The method of claim 1, wherein the logical volume comprises substantially all of the first and second physical storage devices.

10. The method of claim 1, wherein the logical volume comprises only portions of the first and second physical storage devices.

11. The method of claim 1, wherein the logical volume comprises a redundant array of inexpensive disks.

12. The method of claim 11, wherein the logical volume is organized to have a RAID Level of 0, 1, 2, 4, 5, or 6.

13. The method of claim 1, wherein the logical volume does not include actual data that are mirrored between at least two different physical storage devices when the logical volume is accessible.

14. The method of claim 1, wherein the actual data has a size corresponding to a stripe, a line, or a block.

15. An information handling system comprising:

a logical volume including a first physical storage device and a second physical storage device that is different from the first physical storage device;

a cache operable to temporarily store data that is to be persisted within the first physical storage device of the logical volume; and

a processor coupled to the logical volume and the cache, wherein the processor is operable to;

store the data into the cache;

determine whether the logical volume is inaccessible;

persist the data into the second physical storage device in response to determining that the logical volume is inaccessible; and

restore the logical volume.

16. The information handling system of claim 15, wherein restore the logical volume comprises persist the data within the first physical storage device after the logical volume becomes accessible after being inaccessible.

17. The information handling system of claim 15, wherein restore the logical volume comprises persist the data within a third physical storage device after the logical volume becomes accessible, wherein the third physical storage device is part of the logical volume and is different from the first physical storage device and the second physical storage device.

18. The information handling system of claim 15, wherein:

the logical volume includes other physical storage devices;

the processor is further operable to persist the data into each of the other physical storage devices that are available while the logical volume is inaccessible; and

restore the logical volume comprises;

persist actual data within the first physical storage device; and

persist corresponding metadata into each of the first, second, and other physical storage device within the logical volume.

19. The information handling system of claim 18, wherein restore the logical volume further comprises restore the data to the cache from the second physical storage device.

20. The information handling system of claim 15, wherein the processor is further operable to restore access to a host system.