US Patent 9015430 Copy on write storage conservation systems and methods

Systems and methods for copy on write storage conservation are presented. In one embodiment a copy on write storage conservation method includes creating and mounting a snapshot; mounting a snapshot; monitoring interest in the snapshot; initiating a copy on write discard process before a backup or replication is complete; and deleting the snapshot when the backup or replication is complete. In one embodiment the method also includes marking a file as do not copy on write. In one embodiment, the copy on write discard process includes discarding copy on write data when a corresponding read on the file in the snapshot is successful. Initiating a copy on write discard process can be done at a variety of levels (e.g., a file level, an extent level, a block-level, etc.).