Patent ID: 7730277

Claim:
A method for invalidating and replacing a loadable block pointer stored in an indirect block of a volume served by a storage system, the method comprising: assembling a plurality of groups of storage devices of the storage system into an aggregate, the aggregate having a physical volume block number (pvbn) space defining a global storage space provided by the storage devices; storing within the aggregate a plurality of virtual volumes (vvols) of the storage system, each vvol having a file system and a virtual volume block number (vvbn) space, wherein the plurality of virtual volumes allow for two layers of virtualization; converting the loadable block pointer of a block pointer pair of the indirect block into a special block pointer having a predefined reserved value, the predefined reserved value providing an unknown temporary physical volume block number (pvbn_unknown) placeholder until the pvbn_unknown placeholder can be replaced by a real pvbn, wherein the block pointer pair is stored within the indirect block and includes a pvbn pointer and a vvbn pointer and the loadable block pointer is the pvbn pointer; and processing a request to access data by allowing the storage system to serve data from the volume using the special block pointer while an actual block pointer is computed, thereby eliminating latency associated with completion of actual block pointer replacement for the special block pointer.