Patent ID: 7334095

Claim:
A method for creating a writable clone of a read-only volume, comprising: generating a base snapshot within a parent virtual volume (vvol) in an aggregate on a source volume on a source storage system; duplicating the base snapshot as a read-only base snapshot replica on a target volume on a destination storage system; creating a new virtual volume (vvol) on the destination storage system, the new vvol embodied as the clone and includes a container file; modifying a volume information (volinfo) block for the clone, the modified volinfo block comprising a modified version of a volinfo block from the read-only base snapshot replica and the modified volinfo block points to one or more blocks of the source storage system and one or more blocks of the clone; writing the modified volinfo block to the container file; instantiating the clone to service storage requests as the writable clone of a read-only volume; and propagating a clone softlock from the destination storage system to the source storage system to ensure that the source storage system does not delete the base snapshot or parent vvol while the clone exists.