Patent ID: 8903830

Claim:
A computer-implemented method, comprising: organizing a plurality of storage devices into an aggregate, where the aggregate is a physical volume organized into a global storage space, and a data block of a file is resident on a storage device of the plurality of storage devices of the aggregate; providing a plurality of virtual volumes within the aggregate; allocating the data block to a virtual volume (vvol) of the plurality of virtual volumes, the vvol having a virtual volume identification (vvid); selecting a physical volume block number (pvbn) for the data block from a pvbn space of the aggregate; selecting a virtual volume block number (vvbn) for the data block from a vvbn space of the vvol to allocate the data block to the vvol; inserting both the pvbn and the vvbn in a parent block of a buffer tree of the file as block pointers to point to the allocated data block on the storage device; utilizing the pvbn, inserted in the parent block, to access the data block in response to a read request; and utilizing the vvbn, inserted in the parent block, to free the data block.