A technique for using a remote array cache memory for data redundancy. A computer system includes a first storage system having cache memory and mass storage. Data to be written to the mass storage is written to the cache memory. Redundant data is stored elsewhere in case the cache experiences a fault before the data can be written to mass storage. Otherwise, data not yet written to the mass storage may be lost. The first storage system is in communication with a second storage system which is typically located remotely from the first storage system. When the first storage system receives a write request, the first storage system forwards the data to the second storage system for redundant storage. Where the data is forwarded to the second storage system, this is referred to herein as "remote mode." The first storage system may include redundant cache memories and enters remote mode only in the event a fault affects one of the cache memories. The data can then be recovered from the second storage system if needed.