Method for performing periodic replication of data on a remote storage system

• US 7,359,927 B1
• Filed: 12/01/2004
• Issued: 04/15/2008
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Cardente, John
• Primary Examiner(s): Cottingham; John
• Assistant Examiner(s): Alvesteffer; Jason L
• Application Number:
  US11/001,229
• Time in Patent Office: 1,231 Days
• Field of Search: 707/200, 707/201, 707/202, 707/203, 707/204, 707/10, 711/157, 711/161, 711/162
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1461 Backup scheduling policy
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 2201/82 Solving problems relating to consistency ensuring consistency in mirrored systems G06F11/2064
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A method for transferring a copy of data stored at a source to a remote location. The method includes storing at the source sequence of sets of changes in the data stored at the source. The method transfers to a first one of a pair of storage volumes at the remote location the most recent pair of the stored sets of changes in the sequence of data stored at the source at a time prior to such transfer. The method subsequently transferring to a second one of the pair of storage volumes at the remote location the most recent pair of the stored sets of changes in the in the sequence of data stored at the source at a time prior to such subsequent transfer.

Claims

1. A method for transferring a copy of data stored at a source to a remote location, comprising:

(a) storing at the source a first one of a sequence of sets of changes in the data stored at the source;

(b) designating in the source a first one of a pair of storage volumes at the remote location as a target for storage therein of the first one of the stored sets of data changes;

(c) transferring to the targeted first one of a pair of storage volumes the first one of the stored sets of data changes while leaving in storage at the source the first one of the sets of data changes;

(d) designating in the source a second one of a pair of storage volumes at the remote location as a target for storage therein of the first one and a second subsequent one of the sets of changes in data in the sequence thereof,

(e) transferring to the targeted second one of a pair of storage volumes the first one of the stored sets of data changes and the second subsequent one of the sets of changes in data in the sequence thereof while leaving in storage at the source said the first one of the sets of data changes and the second subsequent one of the sets of changes in data in the sequence thereof;

(f) determining from the remote location whether there has been an error in the transferring to the targeted second one of a pair of storage volumes the first one of the stored sets of data changes and the second subsequent one of the sets of changes in data in the sequence thereof while leaving in storage at the source said the first one of the sets of data changes and a second subsequent one of the sets of changes in data in the sequence thereof;

(g) in the absence of an error being determined, removing the first one of the stored sets of data changes and designating in the source the first one of a pair of storage volumes at the remote location as a target for storage therein of the second one and a third subsequent one of the sets of changes in data in the sequence thereof;

(h) transferring to the targeted first one of a pair of storage volumes the second subsequent one of the stored sets of data changes and the third subsequent one of the sets of changes in data in the sequence thereof while leaving in storage at the source said the second and third subsequent one of the sets of changes in data in the sequence thereof; and

(i) in the absence of an error being determined, removing the second one of the stored sets of data changes and designating in the source the second one of a pair of storage volumes at the remote location as a target for storage therein of the third one and a fourth subsequent one of the sets of changes in data in the sequence thereof.

2. The method recited in claim 1 wherein steps (e) through (i) are iteratively repeated for subsequent sets of data changes.