Patent ID: 9087006
Filing Date: 2015-07-21
Classification: G06F

Abstract:
1. A method of operating a storage system which includes a cache memory operatively coupled to a physical storage space comprising a plurality of disk drives, the method comprising performing a plurality of storage recurrences for destaging data from the cache memory to the physical storage space, wherein a performing of each storage recurrence comprises: upon a start of the storage recurrence, destaging first dirty data which had been accommodated in the cache memory prior to the start of said storage recurrence, wherein the destaging of the first dirty data is provided with no overwriting of superseded data that includes data that was destaged before starting said storage recurrence whilst enabling retaining metadata indicative of location of said superseded data in the physical storage space; wherein the destaging of the first dirty data is performed in an order that differs from an order in which the first dirty data had been accommodated in the cache memory; queuing second dirty data accommodated in said cache memory subsequent to the start of said storage recurrence, wherein the queuing of the second dirty data is in a second data structure that differs from a first data structure used for queuing the first dirty data; preventing said second dirty data from being destaged during the performing of said storage recurrence and until a start of a next storage recurrence; and registering a point-in-time indicative of a successful destaging of the first dirty data, thereby providing an order-preservation consistency indication corresponding to said storage recurrence.