Patent ID: 8892817
Filing Date: 2014-11-18
Classification: G11B

Abstract:
1. A method of operating a data storage device having an Indirection Address Table mapping logical block addresses (LBAs) to physical block addresses (PBAs), the method comprising: periodically writing a snapshot of the Indirection Address Table on a disk inline with user data being written in a buffer on the disk, with the snapshot being written after a first block of user data has been written in the buffer and before a second block of user data so that the snapshot is positioned between first and second blocks of user data, each snapshot including a snapshot ID that identifies a last snapshot from earlier snapshots; and after each snapshot is written, making a Delta List that contains a set of entries that record subsequent changes to the Indirection Address Table after the first block of user data has been written, with entries mapping at least one LBA to a PBA for the second block of user data and periodically writing the Delta List to the buffer on the disk, each Delta List including the snapshot ID that identifies the last snapshot.