Method to support hash based xcopy synchronous replication
In one aspect, support for hash based xcopy replication for synchronous replication is provided. An aspect includes determining, in response to an xcopy command, whether a source logical unit (LU) and a target LU are in active synchronous replication to the same target site. Upon determining that the LUs are in active synchronous replication, increasing a count of a hash handle list, obtaining a unique full hash digest, and sending the digest with volume replication pairing identifier, offset, and length to the target. Upon receiving a request from the source, searching, by the target, for local hash handles of the digest; and upon determining the local hash handles exist in the digest, incrementing, the reference counter handle list, and sending corresponding hash handles from the source site to the target.
1. A method for supporting hash-based, extended copy (xcopy) command-enabled synchronous replication at a storage system that includes a source site and a target site, the method comprising:
determining, in response to receiving an xcopy command at the source site, whether the source site and the target site are in active synchronous replication to a same target; and
upon determining that the source site and the target site are in active synchronous replication to the same target:
sending, by the source site, a global unique full hash digest to the target site;
searching, by the target site, for local hash handles of the global unique full hash digest; and
upon determining the local hash handles exist in the global unique full hash digest, sending corresponding hash handles from the source site to the target site.
2. The method of claim 1 , wherein upon determining the local hash handles do not exist in the global unique full hash digest, returning by the target site, information of missing hash handles to the source site.
3. The method of claim 2 , in response to receiving the information of the missing hash handles from the target site, sending by the source site, missing page information corresponding to the missing hash handles to the target site.
4. The method of claim 1 , wherein upon determining the local hash handles exist in the global unique full hash digest, the method further includes:
incrementing, by the target site, a reference count of a hash handle list before sending the corresponding hash handles to the target site.
5. The method of claim 1 , wherein sending the global unique full hash digest to the target site includes sending a volume replication pairing identifier, an offset, and a length.
6. The method of claim 1 , wherein upon determining that the source site and the target site are in active synchronous replication to the same target, the method further comprises:
incrementing, by the source site, a reference count of a hash handle list.
7. The method of claim 1 , further comprising:
upon determining that the source site and the target site are not in active synchronous replication to the same target, obtaining hash handles corresponding to the xcopy command by the source site from a hash handle list at the source site and sending the hash handles to the target site.
8. The method of claim 7 , wherein the hash handles to the target site include a logical unit, an offset, and a length.
9. A system for supporting hash-based, extended copy (xcopy) command-enabled synchronous replication at a storage system including a source site and a target site, the system comprising:
a memory comprising computer-executable instructions; and
a processor operable by the storage system, the processor executing the computer-executable instructions, the computer-executable instructions when executed by the processor cause the processor to perform operations comprising:
determining, in response to receiving an xcopy command at the source site, whether the source site and the target site are in active synchronous replication to a same target; and
upon determining that the source site and the target site are in active synchronous replication to the same target:
sending, by the source site, a global unique full hash digest to the target site;
searching, by the target site, for local hash handles of the global unique full hash digest; and
upon determining the local hash handles exist in the global unique full hash digest, sending corresponding hash handles from the source site to the target site.
10. The system of claim 9 , wherein upon determining the local hash handles do not exist in the global unique full hash digest, the operations further include returning by the target site, information of missing hash handles to the source site.
11. The system of claim 10 , in response to receiving the information of the missing hash handles from the target site, sending by the source site, missing page information corresponding to the missing hash handles to the target site.
12. The system of claim 9 , wherein upon determining the local hash handles exist in the global unique full hash digest, the operations further include:
incrementing, by the target site, a reference count of a hash handle list before sending the corresponding hash handles to the target site.
13. The system of claim 9 , wherein sending the global unique full hash digest to the target site includes sending a volume replication pairing identifier, an offset, and a length.
14. The system of claim 9 , wherein upon determining that the source site and the target site are in active synchronous replication to the same target, the operations further include:
incrementing, by the source site, a reference count of a hash handle list.
15. The system of claim 9 , wherein the operations further include:
upon determining that the source site and the target site are not in active synchronous replication to the same target:
obtaining hash handles corresponding to the xcopy command by the source site from a hash handle list at the source site; and
sending the hash handles to the target site;
wherein the hash handles to the target site include a logical unit, an offset, and a length.
16. A computer program product for supporting hash-based, extended copy (xcopy) command-enabled synchronous replication at a storage system, the computer program product embodied on a non-transitory computer readable medium, the computer program product including instructions that, when executed by a computer, causes the computer to perform operations comprising:
determining, in response to receiving an xcopy command at the source site, whether the source site and the target site are in active synchronous replication to a same target; and
upon determining that the source site and the target site are in active synchronous replication to the same target:
sending, by the source site, a global unique full hash digest to the target site;
searching, by the target site, for local hash handles of the global unique full hash digest; and
upon determining the local hash handles exist in the global unique full hash digest, sending corresponding hash handles from the source site to the target site.
17. The computer program product of claim 16 , wherein the operations further include:
upon determining the local hash handles do not exist in the global unique full hash digest, returning by the target site, information of missing hash handles to the source site; and
in response to receiving the information of the missing hash handles from the target site, sending by the source site, missing page information corresponding to the missing hash handles to the target site.
18. The computer program product of claim 16 , wherein upon determining the local hash handles exist in the global unique full hash digest, the operations further include:
incrementing, by the target site, a reference count of a hash handle list before sending the corresponding hash handles to the target site.
19. The computer program product of claim 16 , wherein sending the global unique full hash digest to the target site includes sending a volume replication pairing identifier, an offset, and a length.
20. The computer program product of claim 16 , wherein upon determining that the source site and the target site are in active synchronous replication to the same target, the operations further include:
incrementing, by the source site, a reference count of a hash handle list.