Patent ID: 9336150
Filing Date: 2016-05-10
CPC Classification: G06F

Claim Text:
1. A system coupled to a cache, the system comprising: a memory; and a processor coupled to the memory, wherein the processor performs operations, the operations comprising: maintaining a plurality of logical subsystems, wherein each logical subsystem stores a plurality of volumes, wherein a logical storage group is a plurality of logical subsystems that is owned for input/output (I/O) operations; receiving a request to perform staging operations with respect to an area of a cache, wherein performing the staging operations with respect to the area of the cache comprises moving one or more extents, tracks, volumes or logical subsystems from one or more disk drives to the area of the cache; in response to determining that one or more discard scans are being performed or queued for the area of the cache, avoiding satisfying the request to perform the staging operations with respect to the area of the cache; in response to determining that the one or more discard scans are being performed or queued for the logical storage group, bypassing the cache for stages, and directly stage from the one or more disk drives; and in response to determining that the one or more discard scans are being performed or queued for a volume, performing: in response to determining from discard task control blocks that the staging operations are not for tracks in a range of tracks being discarded via the discard scans, satisfying the request to perform the staging operations; and in response to determining from the discard task control blocks that the staging operations are for tracks in the range of tracks being discarded via the discard scans, bypassing the cache for stages, and directly stage from the one or more disk drives.