Managing incremental cache backup and restore

1. A method for use in managing incremental cache backup and restore, the method comprising:

quiescing input/output (I/O) operations at a cache module;

taking a first snapshot of a storage object and a second snapshot of a solid state drive (SSD) cache object;

maintaining, via the cache module, a disk bitmap and a cache bitmap to track dirty buffers associated with the storage object;

unquiescing I/O operations at the cache module; and

creating a single backup image comprising the first snapshot and the second snapshot.

2. The method of claim 1 , further comprising:

reading data from the single backup image;

identifying incremental backups; and

restoring the storage object and SSD cache object from the single backup image.

3. The method of claim 2 , further including mapping restored storage objects and SSD cache object.

4. The method of claim 1 , wherein the first and second snapshots are point in time snapshots.

5. The method of claim 1 , wherein the storage object includes at least one of a file, block, or logical unit (LU).

6. The method of claim 1 , wherein:

quiescing I/O operations at the cache module includes redirecting uncached write I/O to the storage object; and

unquiescing I/O operations at the cache module includes disabling redirection of uncached write I/O to the storage object.

7. The method of claim 1 , wherein the single backup image includes a backup header, storage object and SSD cache dirty data blocks, storage object DRL metadata, SSD cache DRL metadata blocks, and cache super block.

8. The method of claim 1 , wherein a memory area occupied by the single backup image is determined by the equation:

backup image size=sizeof(storage object dirty buffers)+(2*backupheadersize)+sizeof(SSD dirty blocks)+sizeof(superblock, DRL metadata blocks)+sizeof(storage DRL).

9. The method of claim 1 , further including reserving in-memory and on-disk storage for storing the bitmaps.

10. A system for use in managing incremental cache backup and restore, the system comprising:

a processor;

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

quiesce I/O operations at a cache module;

take a first snapshot of a storage object and a second snapshot of an SSD cache object;

maintain, via the cache module, a disk bitmap and a cache bitmap to track dirty buffers associated with the storage object;

unquiesce I/O operations at the cache module; and

create a single backup image comprising the first snapshot and the second snapshot.

11. The system of claim 10 , wherein the instructions are further executable to:

read data from the single backup image;

identify incremental backups; and

restore the storage object and the SSD cache object from the single backup image.

12. The system of claim 11 , wherein the instructions are further executable to mapping restored storage objects and SSD cache object.

13. The system of claim 10 , wherein the first and second snapshots are point in time snapshots.

14. The system of claim 10 , wherein the storage object includes at least one of a file, block, or logical unit (LU).

15. The system of claim 10 , wherein:

quiescing I/O operations at the cache module includes redirecting uncached write I/O to the storage object; and

unquiescing I/O operations at the cache module includes disabling redirection of uncached write I/O to the storage object.

16. The system of claim 10 , wherein the single backup image includes a backup header, storage object and SSD cache dirty data blocks, storage object DRL metadata, DRL metadata blocks, and cache super block.

17. The system of claim 10 , wherein a memory area occupied by the single backup image is determined by the equation:

backup image size=sizeof(storage object dirty buffers)+(2*backupheadersize)+sizeof(SSD dirty blocks)+sizeof(superblock, DRL metadata blocks)+sizeof(storage DRL).

18. The system of claim 17 , wherein the instructions are further executable to reserve in-memory and on-disk storage for storing the bitmaps.

19. A computer program product for use in managing incremental cache backup and restore comprising:

a non-transitory computer readable medium encoded with computer executable program code, the code configured to enable the execution of:

quiescing input/output (I/O) operations at a cache module;

taking a first snapshot of a storage object and a second snapshot of a solid state drive (SSD) cache object;

maintaining, via the cache module, a disk bitmap and a cache bitmap to track dirty buffers associates with the storage object;

unquiescing I/O operations at the cache module; and

creating a single backup image comprising the first snapshot and the second snapshot.

20. The computer program product of claim 19 , the code further configured to enable the execution of:

reading data from the single backup image;

identifying incremental backups; and

restoring the storage object and SSD cache object from the single backup image.