Patent ID: 9003113
Filing Date: 2015-04-07
Classification: G06F

Abstract:
1. A method of throttling cache updates in a storage device having a flash memory-based cache and a disk-based storage unit, the method comprising: determining, by a controller of the storage device, a threshold number of writes that are permitted to the flash memory-based cache per write period by dividing a remaining number of writes that can be tolerated by the flash memory-based cache of the storage device into a number of write periods remaining in an expected service lifetime for the storage device, wherein the write periods comprise periods of fixed interval and the threshold number of permitted writes per write period is updated periodically; and for a subject one of the write periods, (i) monitoring, by the controller, a number of writes to the flash memory-based cache during the subject write period, (ii) allowing, at most, the number of writes to the flash memory-based cache during the subject write period to be equal to the determined threshold number of permitted writes for the subject write period, and (iii) if an additional number of writes to the flash memory-based cache are attempted in excess of the determined threshold number of permitted writes for the subject write period, refusing the additional number of writes to the flash memory-based cache and directing the additional number of writes to the disk-based storage unit.