Patent ID: 9003129
Filing Date: 2015-04-07
Classification: G06F

Abstract:
1. A method performed at a first storage processing device (SP), the first SP having a first cache, the first SP being communicatively connected to a second SP having a second cache over a cache mirroring bus, the first cache and the second cache being configured to function as mirrors, the first SP and the second SP being configured to operate in an active/active fashion for processing data storage commands directed at a data storage array, wherein the method comprises: receiving a write command at the first SP from a host computer directed to a particular address of the data storage array; identifying a reference structure in the first cache that is uniquely associated with the particular address, the reference structure pointing to a set of cache pages associated with the particular address, the reference structure having a token count field; determining whether the reference structure is synchronized with a corresponding reference structure in the second cache; if the reference structure is synchronized with the corresponding reference structure, then: if the reference structure is not synchronized with the corresponding reference structure, then: in response to performing the cache write operation, synchronizing the reference structure with the corresponding reference structure by sending a merge message from the first SP to the second SP over the cache mirroring bus, the merge message including the cache page on which the cache write operation was performed to be copied to the second cache.