Method for Remote Asynchronous Replication of Volumes and Apparatus Therefor
First Claim
1. A method for asynchronous replication of volumes, comprising:
- mirroring a source volume located on a first site to a destination volume located on a second site;
receiving a Host input/output (IO) request, wherein the Host IO request is sent from a host located on the first site for writing an updated data set into a first data block of the source volume;
executing a backup-on-write operation, wherein the backup-on-write operation firstly determines whether an original data set of the first data block of the source volume is the same with a data set of a second data block, corresponding to the first data block, of the destination volume, so as to determine whether the original data set of the first data block of the source volume is backuped to a first backup image located on the first site or not;
writing the updated data set into the first data block of the source volume; and
responding the host that the Host IO request has been completed.
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Abstract
A method for remote asynchronous volume replication and apparatus therefore are disclosed. Asynchronous replication is applied to deal with data changes on the source volume on the local site incurred by Host IO requests. In coordination with the “point-in-time differential backup” technology, the data is subjected to be backuped to Source BAS on the local site (backup-on-write operation) only when the original data being written into the block of the source volume is different from the data of the corresponding block of the destination volume on the remote site. As a result, once a new data is written into the source volume completely, the host will be responded that its Host IO request is completed. Therefore, the data necessarily transmitted to the destination volume on the remote site can be minimized, and the problem of remote data transmission limited by network bandwidth can be prevented effectively, thereby keeping the operation performance of the storage system at a better level.
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Citations
44 Claims
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1. A method for asynchronous replication of volumes, comprising:
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mirroring a source volume located on a first site to a destination volume located on a second site; receiving a Host input/output (IO) request, wherein the Host IO request is sent from a host located on the first site for writing an updated data set into a first data block of the source volume; executing a backup-on-write operation, wherein the backup-on-write operation firstly determines whether an original data set of the first data block of the source volume is the same with a data set of a second data block, corresponding to the first data block, of the destination volume, so as to determine whether the original data set of the first data block of the source volume is backuped to a first backup image located on the first site or not; writing the updated data set into the first data block of the source volume; and responding the host that the Host IO request has been completed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A system for asynchronous volume replication, comprising:
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a first storage virtualization subsystem located on a first site, comprising a first controller and a first storage unit, wherein the first storage unit has a first volume and a first backup image; a second storage unit located on a second site, wherein the second storage unit has a second volume; and a host located on the first site and coupled with the first storage virtualization subsystem, wherein the host sends a Host IO request to the first volume of the first storage virtualization subsystem; wherein when the first controller of the first storage virtualization subsystem receives the Host IO request, a backup-on-write operation is executed to determine whether an original data set of a first data block, which is to be written, of the first volume is the same with a data set of a second data block, corresponding to the first data block, of the second volume, so as to determine whether the original data of the first data block of the first volume is backuped to the first backup image or not; writing an updated data of the Host IO request into the first data block of the first volume by the first controller; and responding the host that the Host IO request is completed. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44)
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Specification