Configuring I/O cache

1. A method for use in configuring I/O cache, the method comprising:

identifying a file system and a disk volume;

mounting the file system on the disk volume;

determining that at least a portion of the disk volume will be unavailable for I/O for at least a first time;

creating a cache mapper logical volume in response to the determining that at least the portion of the disk volume will be unavailable for I/O for at least the first time;

creating a cache volume from an existing cache storage unit, wherein the cache mapper logical volume is mounted on the disk volume and the cache volume, and wherein the cache volume is created on a solid state drive; and

relocating data from the disk volume to the cache volume;

wherein I/O operations are directed between the file system and the disk volume in response to cache volume creation not being completed; and

wherein I/O operations are directed from the file system to the cache volume in response to cache volume creation being completed.

2. The method of claim 1 , further comprising queuing I/O operations during cache volume creation.

3. The method of claim 2 , farther comprising directing queued I/O operations to the cache volume after cache volume creation.

4. The method of claim 1 , wherein the cache mapper is created while the file system is mounted.

5. The method of claim 1 , further comprising including dynamically deconstructing the cache mapper and cache volume in response to a destructor request.

6. The method of claim 1 , further comprising dynamically deconstructing the cache mapper and cache volume while the file system is mounted.

7. The method of claim 1 , further comprising, in response to a cache hit, directing I/O operations to the cache volume for processing.

8. The method of claim 1 , further comprising, in response to a cache miss, directing I/O operations to the disk volume for processing.

9. The system of claim 1 , wherein the instructions are further executable to queue I/O operations during cache volume creation.

10. The system of claim 9 , wherein the instructions are further executable to direct queued I/O operations to the cache volume after cache volume creation.

11. The method of claim 1 , wherein the disk volume from which data is relocated has been scheduled to undergo a disk spin down.

12. The method of claim 11 , further comprising relocating the data back to the disk volume responsive to one or more disks for the disk volume from which data is relocated spinning back up.

13. The method of claim 1 , further comprising relocating the data back to the disk volume once the first time concludes, the relocating the data back to the disk volume including writing to the disk volume any changes to the data that occurred while located at the cache volume.

14. A system, comprising:

a processor; and

a memory accessible to the processor and bearing instructions executable by the processor to:

identify a file system and a disk volume;

mount the file system on the disk volume;

determine that at least a portion of the disk volume will be unavailable for I/O for at least a first time;

create a cache mapper logical volume in response to the determination that at least the portion of the disk volume will be unavailable for I/O for at least the first time;

create a cache volume from an existing cache storage unit, wherein the cache mapper logical volume is mounted on the disk volume and the cache volume, and wherein the cache volume is created on a solid state drive; and

relocate data from the disk volume to the cache volume;

wherein I/O operations are directed between the file system and the disk volume in response to cache volume creation not being completed; and

wherein I/O operations are directed from the file system to the cache volume in response to cache volume creation being completed.

15. The system of claim 14 , wherein the instructions are further executable to create the cache mapper while the file system is mounted.

16. The system of claim 14 , wherein the instructions are further executable to dynamically deconstruct the cache mapper and cache volume in response to a destructor request.

17. The system of claim 14 , wherein the instructions are further executable to deconstruct the cache mapper and cache volume while the file system is mounted.

18. The system of claim 14 , wherein the instructions are further executable to, in response to a cache hit, direct I/O operations to the cache volume for processing.

19. The system of claim 14 , wherein the instructions are further executable to, in response to a cache miss, direct I/O operations to the disk volume for processing.

20. A computer program product stored in a non-transitory computer readable storage medium, the computer program product comprising instructions that, when executed by an information handling system, causes the information handling system to perform actions to:

identify a file system and a disk volume;

mount the file system on the disk volume;

determine that at least a portion of the disk volume will be unavailable for I/O for at least a first time;

create a cache mapper logical volume in response to the determination that at least the portion of the disk volume will be unavailable for I/O for at least the first time;

create a cache volume from an existing cache storage unit, wherein the cache mapper logical volume is mounted on the disk volume and the cache volume, and wherein the cache volume is created on a solid state drive; and

relocate data from the disk volume to the cache volume;

wherein I/O operations are directed between the file system and the disk volume in response to cache volume creation not being completed; and

wherein I/O operations are directed from the file system to the cache volume in response to cache volume creation being completed.