REPLICATION AND RESTORATION OF SINGLE-INSTANCE STORAGE POOLS

• US 20080244204A1
• Filed: 03/29/2007
• Published: 10/02/2008
• Est. Priority Date: 03/29/2007
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Data Speed Technology LLC (Empire IP LLC)
• Inventors: Cremelie, Nick, De Coninck, Tom, D'Hoye, Koen, Custers, Joris
• Granted Patent: US 7,769,971 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/2038 with a single idle spare processing component
• 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: Y10S 707/99955 Archiving or backup

Abstract

A system and method for managing single instance storage. A computer system includes at least two backup servers, each backup server included in a single-instance storage pool. A first backup server conveys a first de-duplicated list identifying data segments from the first storage pool to a second backup server. The first backup server receives from the second backup server a second de-duplicated list identifying a subset of the data segments and conveys the subset of the data segments to the second backup server. In response to receiving the first list from the first backup server, the second backup server de-duplicates the first list against a second storage pool and conveys the second list to the first backup server. In response to receiving the subset of the data segments, the second backup server adds the received data segments to the second storage pool.

Claims

1. A computer system comprising:

a first storage pool; and

a second storage pool;

wherein a first backup server of the first storage pool is configured to;

convey a first de-duplicated list identifying one or more data segments from the first storage pool to a second backup server associated with the second storage pool;

receive from the second backup server a second de-duplicated list identifying at least a subset of the one or more data segments; and

convey the subset of the one or more data segments to the second storage pool.

2. The system as recited in claim 1,

wherein in response to receiving the first list from the first backup server, the second backup server is configured to:

de-duplicate the first list against the second storage pool to create the second de-duplicated list; and

convey the second de-duplicated list to the first backup server;

wherein in response to receiving said subset of the one or more data segments, the second backup server is further configured to add the subset of the one or more data segments to the second storage pool.

3. The system as recited in claim 2, further comprising one or more clients,

wherein for each data segment stored in the first or the second storage pool, there is stored a fingerprint that identifies the data segment and a reference to each client from which a copy of the data segment was received for backup;

and

wherein to de-duplicate the first list, the second backup server is further configured to de-duplicate the data segments and each data segment'"'"'s associated references against the second storage pool.

4. The system as recited in claim 3, wherein the fingerprints identifying the data segments are encrypted.

5. The system as recited in claim 2, further comprising one or more clients, wherein each client is configured to:

assemble a batch of data segments including only data segments that do not have a backup copy already stored in the first storage pool; and

convey the assembled batch to the first backup server.

6. The system as recited in claim 5,

wherein each client is configured to assign a batch number to the data segments and references in the assembled batch;

and

wherein the first backup server is further configured to;

store batch numbers in a backup history;

select only data segments and references for inclusion in the first list whose batch numbers are stored in the backup history; and

clear the backup history after each replication.

7. The system as recited in claim 2, wherein in response to a request to reverse replicate at least a portion of a second storage pool, the second backup server is configured to:

convey a first de-duplicated reverse list identifying one or more data segments to the first backup server;

receive from the first backup server a second de-duplicated reverse list identifying at least a subset of the one or more data segments of the first de-duplicated reverse list; and

convey the at least a subset of the one or more data segments to the first backup server;

wherein in response to receiving the first reverse list from the second backup server, the first backup server is configured to;

de-duplicate the first reverse list against the first storage pool; and

convey the second de-duplicated reverse list to the second backup server; and

wherein in response to receiving the at least a subset of the one or more data segments, the first backup server is further configured to add the at least a subset of the one or more data segments to the first storage pool.

8. A method of replicating single-instance storage pools between backup servers, the method comprising a first backup server:

conveying a first de-duplicated list identifying one or more data segments from a first storage pool to a second backup server associated with a second storage pool;

receiving from the second backup server a second de-duplicated list identifying at least a subset of the one or more data segments; and

conveying the at least a subset of the one or more data segments to the second backup server.

9. The method as recited in claim 8, further comprising the second backup server:

de-duplicating the first de-duplicated list against the second storage pool to create a second de-duplicated list, in response to receiving the first list from the first backup server;

conveying the second de-duplicated list to the first backup server; and

the first backup server adding the subset of the one or more data segments to the first storage pool in response to receiving said subset.

10. The method as recited in claim 9, further comprising:

for each data segment stored in the first or the second storage pool, storing a fingerprint that identifies the data segment and a reference to each of one or more clients from which a copy of the data segment was received for backup; and

wherein de-duplicating the first list against a second storage pool further comprises de-duplicating the data segments and each data segment'"'"'s associated references against the second storage pool.

11. The method as recited in claim 10, wherein the fingerprints identifying the data segments are encrypted.

12. The method as recited in claim 9, further comprising:

assembling a batch of data segments including only data segments that do not have a backup copy already stored in the first storage pool; and

conveying the assembled batch to the first backup server.

13. The method as recited in claim 12, further comprising:

assigning a batch number to the data segments and references in the assembled batch; and

in response to receiving an assembled batch;

storing a batch number in a backup history;

selecting only data segments and references for inclusion in the first list whose batch numbers are stored in the backup history; and

clearing the backup history after each replication.

14. The method as recited in claim 9, further comprising

the second backup server:

conveying a first de-duplicated reverse list identifying one or more data segments from the second storage pool to the first backup server;

receiving from the first backup server a second de-duplicated reverse list identifying at least a subset of the one or more data segments of the first de-duplicated reverse list; and

conveying the at least a subset of the one or more data segments to the first backup server; and

the first backup server;

de-duplicating the first de-duplicated reverse list against the first storage pool, in response to receiving the first reverse list from the second backup server;

conveying the second de-duplicated reverse list to the second backup server; and

adding the at least a subset of the one or more data segments to the first storage pool in response to receiving the at least a subset of the one or more data segments.

15. A computer readable medium storing computer instructions that are executable by a processor to:

cause a first backup server to;

convey a first de-duplicated list identifying one or more data segments from the first storage pool to a second backup server associated with a second storage pool;

receive from the second backup server a second de-duplicated list identifying at least a subset of the one or more data segments; and

convey the at least a subset of the one or more data segments to the second backup server.

16. The computer readable medium as recited in claim 15, wherein the instructions are further executable to cause the second backup server to:

de-duplicate the first list against the second storage pool, in response to receiving the first list from the first backup server;

convey the second de-duplicated list to the first backup server; and

cause the first backup server to add the at least a subset of the one or more data segments to the first storage pool in response to receiving the at least a subset of the one or more data segments.

17. The computer readable medium as recited in claim 16, wherein the instructions are further executable to:

for each data segment stored in the first or the second storage pool, store an associated fingerprint identifying the data segment and a reference to each of one or more clients from which a copy of the data segment was received for backup, wherein the list includes each data segment'"'"'s associated references; and

wherein to de-duplicate the first list against a second storage pool further comprises de-duplicating the data segments and each data segment'"'"'s associated references against the second storage pool.

18. The computer readable medium as recited in claim 17, wherein the fingerprints identifying the data segments are encrypted.

19. The computer readable medium as recited in claim 16, wherein the instructions are further executable to:

assemble a batch of data segments including only data segments that do not have a backup copy already stored in the first storage pool; and

convey the assembled batch to the first backup server.

20. The computer readable medium as recited in claim 19, wherein the instructions are further executable to:

assign a batch number to the data segments and references in the assembled batch; and

in response to receiving an assembled batch;

store a batch number in a backup history;

select only data segments and references for inclusion in the first list whose batch numbers are stored in the backup history; and

clear the backup history after each replication.