INCREMENTAL TRANSFER WITH UNUSED DATA BLOCK RECLAMATION

摘要

One or more techniques and/or systems are provided for incremental transfer with unused data block reclamation. For example, source volume of a source storage filer may have a physical replication relationship with a destination volume of a destination storage filer. Snapshots of a file system of the source volume may be used to identify new data blocks (e.g., data blocks allocated or reallocated to a new snapshot) and/or unused data blocks (e.g., data blocks of a deleted snapshot) used to incrementally update the destination volume so that the destination volume is a mirrored replication of the source volume. In this way, new data blocks may be updated and unused data blocks may be punched out (e.g., deallocated) of the destination volume during execution of an incremental update.

主权项

1. A method comprising:
determining, by a storage server, that a prior incremental transfer utilized a base snapshot of a source volume of a source storage filer for physical replication of data blocks to a destination volume of a destination storage filer; determining that a snapshot of the source volume was deleted after the prior incremental transfer; and responsive to determining that a new incremental transfer, from the source volume to the destination volume, is to be performed subsequent the prior incremental transfer:
determining that a new snapshot of the source volume was created subsequent the prior incremental transfer;comparing a first active map of the base snapshot with a second active map of the new snapshot to identify a set of new data blocks, allocated to the new snapshot, to transfer to the destination volume using the new incremental transfer;comparing the first active map and a first summary map of the base snapshot with the second active map and a second summary map of the new snapshot to identify a set of unused data blocks previously allocated to the snapshot that was deleted from the source volume; andimplementing the new incremental transfer comprising an instruction for the destination storage filer to punch out the set of unused data blocks from the destination volume and to write the set of new data blocks to the destination volume.