METHOD AND SYSTEM TO MAINTAIN MAXIMUM PERFORMANCE LEVELS IN ALL DISK GROUPS BY USING CONTROLLER VDs FOR BACKGROUND TASKS
AssigneeLSI Corporation
InventorsHariharan T., Madan Mohan Munireddy
Life of this patent
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Abstract
Disclosed is a system and method for performing reconstruction or on-line capacity expansion, background tasks, on a disk group configured on a controller with minimal impact on the other disk groups configured on the same controller. A user is enabled to continuously experience increased performance on all source virtual disks configured on the controller since the DRAM is always dedicated for I/O performance.
Claims11
A method of performing a background operation on a first disk group while at least one other disk group performs normal caching, wherein each of said first and other disk groups comprises cache contents, said method comprising:
- determining if there are any write-through Secondary Cache disks configured;
- if a write-through disk is configured;
- invalidating the cache contents of the write-through Secondary Cache disk;
- dissociating the Secondary Cache write-through disk from a source disk;
- and
- using the write-through Secondary Cache disk for the background function;
- if a write-through Secondary Cache disk is not configured;
- identifying a suitable write-back Secondary Cache disk;
- flushing the cached contents of the suitable write-back Secondary Cache disk to a respective source disk;
- dissociating the write-back Secondary Cache disk from the source disk;
- and
- using the write-back Secondary Cache disk for the background operation;
- and
- upon completing of the background operation;
- restoring Secondary Cache disk cache policies;
- and
- reverting any dissociated disks back to being associated with a source disk as originally associated.
A system for performing background tasks on a plurality of disk groups, said system comprising:
- a controller enabled to perform the background tasks on said plurality of disks, wherein:
- the controller determines if a write-through virtual disk is configured;
- if a write-through virtual disk is configured, the controller invalidates any contents of the write-through disk cache;
- if a write-through virtual disk is not configured, the controller identifies a suitable write-back virtual disk and flushes data from the write-back virtual disk;
- the controller uses the virtual disk for the background task;
- and
- when the background task is complete, the controller reverts the virtual disk associations and cache policies back.
Dependencies are inferred from the claim text.