System and method for maintaining cache coherency

A method comprising:

• receiving a notification that a device generation identifier (ID) stored on a primary storage device coupled to a cache memory of a storage system is less than a current generation ID of the cache memory, wherein the current generation ID is associated with a last time cache data was written to the cache memory and wherein the device generation ID is associated with a restored backup of the primary storage device;
• and
• based on receiving the notification:
• (1) marking, by a processor of the storage system, first cache data of the cache data as invalid based on the first cache data being associated with a different generation ID that is greater than the device generation ID stored on the primary storage device,
• (2) receiving a first data access request for the first cache data from a client, and
• (3) preventing transmission of the first cache data from the cache memory to the client based on marking the first cache data as invalid.

A non-transitory computer readable storage medium containing executable program instructions configured for execution by a processor and further configured for storage on the non-transitory computer readable storage medium, the computer readable storage medium comprising:

• program instructions that receive a notification that a device generation identifier (ID) stored on a primary storage device coupled to a cache memory of a storage system is less than a current generation ID of the cache memory, wherein the current generation ID is associated with a last time cache data was written to the cache memory and wherein the device generation ID is associated with a restored backup of the primary storage device;
• and
• based on receiving the notification, program instructions that:
• (1) mark first cache data of the cache data as invalid based on the first cache data being associated with a different generation ID that is greater than the device generation ID stored on the primary storage device, (2) receive a first data access request for the first cache data from a client, and (3) prevent transmission of the first cache data from the cache memory to the client based on marking the first cache data as invalid.