A method for copy on write (COW) operations generally includes receiving a write request to a first node in an ordered data structure and updating a write ahead log record associated with COW operation with, instead of the content of the first node, a physical disk address of a second node owned by the run point in the ordered data structure that is a parent node of the first node, a pointer to the first node in the second node, a physical disk address of the first node, and a physical disk address of the third node. A metadata table record for a snapshot that owns the first node may be updated with a log sequence number (LSN) of the COW operation. A method for deleting a snapshot includes determining whether the COW operation recorded in the WAL record for the LSN is completed before deleting the snapshot.