Solid state drive cache recovery in a clustered storage system

A method, comprising:

• maintaining, by each node out of multiple nodes of a storage system, a solid state disk (SSD) cache map that comprises multiple entries for storing mappings from logical addresses to SSD cache physical addresses and to hard disk drives (HDDs) physical addresses;
• wherein the mappings are related to data units stored in the SSD cache;
• wherein the multiple nodes are coupled to hard disk drives and each node comprises a solid state drive (SSD) cache and a management module;
• and
• performing a recovery process of a certain node, upon a rejoin of the certain node following a shut-down or a failure of the certain node, wherein the recovery process comprises:
• obtaining from at least one other node, current mappings between logical addresses and HDDs Physical addresses, and
• performing a validation process of the data units stored in the SSD cache in response to relationships between the current mappings and the entries of the SSD cache map.

A non-transitory computer readable medium that stores instructions for:

• maintaining, by each node out of multiple nodes of a storage system, a solid state disk (SSD) cache map that comprises multiple entries for storing mappings from logical addresses to SSD cache physical addresses and to hard disk drives (HDDs) physical addresses;
• wherein the multiple nodes are coupled to hard disk drives and each node comprises a SSD cache and a management module;
• and
• performing a recovery process of a certain node upon a rejoin of a certain node following shut-down or a failure of the certain node, wherein the recovery process comprises (a) obtaining from at least one other node, current mappings between logical addresses and HDDs physical addresses, and (b) performing a validation process of the entries of the SSD cache is response to relationships between the current mappings and the entries of the SSD cache map.