Resynchronization of a remote storage site after replication failure

Patent metadata

Field	Value
Publication number	US-2016371007-A1
Application number	US-201514742741-A
Country	US
Kind code	A1
Filing date	Jun 18, 2015
Priority date	Jun 18, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

A method for replicating a local storage entity to provide a remote storage entity, the method may include receiving, by a local storage site, after an occurrence of a replication failure, after-failure remote storage site difference information indicative of differences between (i) a certain point in time version of the remote storage entity and (ii) an after-failure point in time version of the remote storage entity; calculating, by the local storage site, after the occurrence of the replication failure, after-failure local storage site difference information indicative of differences between (i) a certain point in time version of the local storage entity and (ii) an after-failure point in time version of the local storage entity; and sending, by the local storage site to the remote storage site, local storage entity portions listed in at least one of the after-failure remote storage site difference information and to the after-failure local storage site difference information, during an after-failure replication cycle; and wherein the certain point in time is associated with a last successful replication cycle that preceded the replication failure.

First claim

We claim:

1 . A method for replicating a local storage entity to provide a remote storage entity, the method comprises:
receiving, by a local storage site, after an occurrence of a replication failure, after-failure remote storage site difference information indicative of differences between (i) a certain point in time version of the remote storage entity and (ii) an after-failure point in time version of the remote storage entity; calculating, by the local storage site, after the occurrence of the replication failure, after-failure local storage site difference information indicative of differences between (i) a certain point in time version of the local storage entity and (ii) an after-failure point in time version of the local storage entity; and sending, by the local storage site to the remote storage site, local storage entity portions listed in at least one of the after-failure remote storage site difference information and to the after-failure local storage site difference information, during an after-failure replication cycle; and wherein the certain point in time is associated with a last successful replication cycle that preceded the replication failure.

2 . The method according to claim 1 wherein the local storage entity portions sent during the after-failure replication cycle comprise all local storage entity portions that are listed in either one of the after-failure remote storage site difference information and the after-failure local storage site difference information.

3 . The method according to claim 1 further comprising participating by the local storage site in a sequence of replication cycles that starts at the after final replication cycle.

4 . The method according to claim 1 wherein the calculating of the after-failure local storage site difference information comprises calculating differences between a certain point in time snapshot of the local storage entity and the after-failure point in time version of the local storage entity.

5 . The method according to claim 1 wherein the after-failure remote storage site difference information consists essentially of addresses within the remote storage entity whose content was changed between the certain point in time and the after-failure point in time.

6 . The method according to claim 1 wherein the after-failure remote storage site difference information comprises addresses within the remote storage entity whose content was changed between the certain point in time and the after-failure point in time.

7 . The method according to claim 1 further comprising calculating, by the remote storage site, after the occurrence of the replication failure, the after-failure remote storage site difference information.

8 . A method for replicating a local storage entity to provide a remote storage entity, the method comprises:
calculating, by a remote storage site, after an occurrence of a replication failure, after-failure remote storage site difference information indicative of differences between (i) a certain point in time version of the remote storage entity and (ii) an after-failure point in time version of the remote storage entity; sending to a local storage site the after-failure remote storage site difference information; receiving, by the remote storage site, after the occurrence of the replication failure, local storage entity portions during an after-failure replication cycle; wherein the local storage entity portions are listed in at least one of the after-failure remote storage site difference information and after-failure local storage site difference information; and updating the remote storage entity with the local storage entity portions that were received during an after-failure replication cycle; wherein the after-failure local storage site difference information is indicative of differences between (i) a certain point in time version of the local storage entity and (ii) an after-failure point in time version of the local storage entity; and wherein the certain point in time is associated with a last successful replication cycle that preceded the replication failure.

9 . The method according to claim 8 wherein the storage entity portions sent during the after-failure replication cycle comprises all local storage entity portions that are listed in either one of the after-failure remote storage site difference information and the after-failure local storage site difference information.

10 . The method according to claim 8 wherein the calculating of the after-failure remote storage site difference information comprises calculating differences between a certain point in time snapshot of the remote storage entity and the after-failure point in time version of the remote storage entity.

11 . The method according to claim 8 further comprising participating by the remote storage site in a sequence of replication cycles that starts at the after final replication cycle.

12 . A non-transitory computer readable medium that stores instructions that once executed by a local storage site cause the local storage site to:
receive after an occurrence of a replication failure, after-failure remote storage site difference information indicative of differences between (i) a certain point in time version of a remote storage entity and (ii) an after-failure point in time version of the remote storage entity; calculate after the occurrence of the replication failure, after-failure local storage site difference information indicative of differences between (i) a certain point in time version of a local storage entity and (ii) an after-failure point in time version of the local storage entity; and send to the remote storage site, local storage entity portions listed in at least one of the after-failure remote storage site difference information and to the after-failure local storage site difference information, during an after-failure replication cycle; and wherein the certain point in time is associated with a last successful replication cycle that preceded the replication failure.

13 . The non-transitory computer readable medium according to claim 12 wherein the local storage entity portions sent during the after-failure replication cycle comprise all local storage entity portions that are listed in either one of the after-failure remote storage site difference information and the after-failure local storage site difference information.

14 . The non-transitory computer readable medium according to claim 12 that stores instructions that once executed by a local storage site cause the local storage site to participate in a sequence of replication cycles that starts at the after final replication cycle.

15 . The non-transitory computer readable medium according to claim 12 wherein the calculating of the after-failure local storage site difference information comprises calculating differences between a certain point in time snapshot of the local storage entity and the after-failure point in time version of the local storage entity.

16 . The non-transitory computer readable medium according to claim 12 wherein the after-failure remote storage site difference information consists essentially of addresses within the remote storage entity whose content was changed between the certain point in time and the after-failure point in time.

17 . The non-transitory computer readable medium according to claim 12 wherein the after-failure remote storage site difference information comprises addresses within the remote storage entity whose content was changed between the certain point in time and

Assignees

• Infinidat Ltd

Inventors

• Shani Ayelet

Classifications

• G06F3/067

  Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS] · CPC title

• G06F3/0614

  Improving the reliability of storage systems · CPC title

• G06F3/065 Primary

  Replication mechanisms · CPC title

• G06F11/14

  Error detection or correction of the data by redundancy in operations (error detection or correction of the data by redundancy in hardware G06F11/16) · CPC title

• G06F11/1464 Primary

  for networked environments · CPC title