Triangular asynchronous replication

Patent metadata

Field	Value
Publication number	US-9558083-B2
Application number	US-201113275706-A
Country	US
Kind code	B2
Filing date	Oct 18, 2011
Priority date	Sep 30, 2004
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

Storing recovery data includes providing chunks of data to a remote destination, where each chunk of data represents data written before a first time and after a second time and where the second time for one of the particular chunks corresponds to a first time for a subsequent one of the particular chunks, providing synchronous data to a local destination, and providing an indicator to the local destination in connection with creation of a new chunk of data for storage at the remote destination. The local destination may maintain a plurality of maps, where each of the maps associates synchronous data being provided thereto with a specific chunk of data. In response to receiving an indicator in connection with creation of a new chunk of data, the local destination may point to a new map. There may be two maps or more than two maps.

First claim

What is claimed is:

1. A method for a remote storage device to facilitate storing recovery data, the method comprising:
receiving an indicator corresponding to failure of at least some of a first set of data to be synchronously transferred from a local storage device to an intermediate storage device, the first set of data corresponding to writes to the local storage device;
receiving a second set of data asynchronously transferred from the local storage device to the remote storage device; and
maintaining at least one map at the remote storage device that indicates differences between portions of the first set of data and portions of the second set of data.

2. A method, according to claim 1 , wherein the second set of data corresponds to chunks of data accumulated at the local storage device, wherein data written to the local storage device after a first time and before a second time is associated with a first chunk of data and data written to the local storage device after the second time is associated with a second chunk of data different than the first chunk of data.

3. A method, according to claim 2 , wherein, in response to receiving an indicator in connection with creation of a new chunk of data, the remote storage device points to a new map.

4. A method, according to claim 3 , wherein there are two maps.

5. A method, according to claim 3 , wherein there are more than two maps.

6. Computer software, provided in a non-transitory computer-readable medium, comprising:
executable code that causes a remote storage device to receive an indicator corresponding to failure of at least some of a first set of data to be synchronously transferred from a local storage device to an intermediate storage device, the first set of data corresponding to writes to the local storage device;
executable code that causes the remote storage device to receive a second set of data asynchronously transferred from the local storage device to the remote storage device; and
executable code that maintains at the remote storage device at least one map that indicates differences between portions of the first set of data and portions of the second set of data.

7. Computer software, according to claim 6 , wherein the second set of data corresponds to chunks of data accumulated at the local storage device, wherein data written to the local storage device after a first time and before a second time is associated with a first chunk of data and data written to the local storage device after the second time is associated with a second chunk of data different than the first chunk of data.

8. Computer software, according to claim 7 , further comprising:
executable code that causes the local destination to point to a new map in response to receiving an indicator in connection with creation of a new chunk of data.

9. Computer software, according to claim 8 , wherein there are two maps.

10. Computer software, according to claim 8 , wherein there are more than two maps.

Assignees

• Lecrone Douglas E
• Cox Gary H
• Quinn Brett A
• Meiri David
• Halstead Mark J
• Yoder Benjamin W
• Emc Ip Holding Co Llc

Inventors

• Lecrone Douglas E
• Cox Gary H
• Quinn Brett A
• Meiri David
• Halstead Mark J
• Yoder Benjamin W

Classifications

• G06F11/2069

  Management of state, configuration or failover · CPC title

• G06F11/2082 Primary

  Data synchronisation · CPC title

• G06F11/2058 Primary

  using more than 2 mirrored copies · CPC title

• G06F11/2074

  Asynchronous techniques · CPC title

• G06F11/2079

  Bidirectional techniques · CPC title