Method for replicating snapshot volumes between storage systems

• US 20080250215A1
• Filed: 06/10/2008
• Published: 10/09/2008
• Est. Priority Date: 04/18/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shitomi, Hidehisa
• Granted Patent: US 7,930,498 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1662 the resynchronized component or unit being a persistent storage device re-synchronization of failed mirror storage G06F11/2082; rebuild or reconstruction of parity RAID storage G06F11/1008
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data

Abstract

An apparatus, system, and method for replicating a snapshot volume in a first storage system to a second storage system includes mapping information corresponding to data in the first storage system that is transferred from the first storage system to the second storage system so that a file system in the second storage system can mount the data after replication. Replication of the snapshot volume can be accomplished using a remote copy mechanism. The snapshot volume can be obtained from a primary source volume P-VOL and a differential source volume D-VOL. If the corresponding destination volumes are not known, a search is conducted to locate appropriate volumes in the second storage system. Mapping information regarding these destination volumes is utilized to enable the file system in the second storage system to mount the replicated snapshot volume.

Claims

1. A method of replicating a snapshot volume in a first storage system to a second storage system, the method comprising the steps of:

providing a primary volume (P-VOL), which represents data initially existing in a first storage system;

providing a differential volume (D-VOL) containing information regarding a change in data of the primary volume for use in recreating the data of the primary volume at predetermined points in time;

storing mapping information of P-VOL and D-VOL in a first snapshot volume management table;

designating a target volume in the second storage system;

storing transfer information including the mapping information of P-VOL and D-VOL and information of the target volume in a copy pair management table;

commencing replication of the P-VOL and D-VOL from the first storage system to the target volume in the second storage system; and

sending the transfer information to the second storage system.