Maintaining cache validity

A computer system for managing a storage array in a storage system, the storage system comprising a first storage device, a second storage device, a source storage device, a target storage device, and a cache, the system comprising:

• one or more processors;
• a memory coupled to at least one of the processors;
• and
• a set of computer program instructions stored in the memory and executed by at least one of the processors in order to perform actions of:
• receiving a first host access request for a data block on the first storage device;
• receiving a mapping between the source storage device and the target storage device;
• and
• responsive to the first host access request and the mapping:
• accessing a corresponding data block on the second storage device;
• and
• updating metadata for the cache.

A computer program product for managing a storage array in a storage system, the computer program product comprising:

• a non-transitory tangible storage device having program code embodied therewith, the program code executable by a processor of a computer to perform a method, the method comprising:
• receiving a first host access request for a data block on the first storage device;
• receiving a mapping between the source storage device and the target storage device;
• and
• in response to the first host access request and the mapping:
• accessing a corresponding data block on the second storage device;
• and
• updating metadata for the cache.