Patent ID: 7131027
Filing Date: 2006-10-31
Classification: G06F

Abstract:
1. A method for linking external storage systems comprising: creating a virtual volume mapping at one or more storage systems, each virtual volume mapping at each storage system associating a virtual storage volume with at least one of a physical storage volume and at least one second virtual storage volume at least one second storage system; receiving an access request at a first storage system specifying a virtual volume, determining on which storage system a physical storage volume associated with the specified virtual volume in the access request is located using at least one of the virtual volume mapping at the first storage system and virtual volume mapping at one or more second storage systems; and providing access to said physical storage volume based on which storage system the physical storage volume is located; wherein the access request comprises a data write request; further comprising checking if the virtual volume has an associated cache, determining if the specified virtual volume in the access request is mapped to a physical storage volume at the first storage system or a second virtual storage volume at least one second storage system, if no cache exists, writing write data associated with the access request into the physical storage volume at the first storage system if the specified virtual volume in the access request is mapped to a physical storage volume at the first storage system; and determining if an error was detected during the writing the write data associated with the access request into the physical storage volume at the first storage system, and recording the error if detected.