HP StorageWorks SAN Virtualization Services Platform administrator guide (5697-0109, July 2009)

Result on destination async
mirror group
Result on source async
mirror group
Async mirror
group to specify
Task
Remote replication to the des-
tination is allowed. If applic-
able, begins log merging or
full copy to the destination.
Remote replication from the
source is allowed. If applic-
able, begins log merging or
full copy from the source.
Source
Resume remote replica-
tion in an asynchronous
mirror group pair.
If the asynchronous mirror
group pair is not in its home
configuration a failover oc-
curs. Otherwise, there is no
change in operation.
If the asynchronous mirror
group pair is not in its home
configuration a failover oc-
curs. Otherwise, there is no
change in operation.
Destination
Revert an asynchronous
mirror group pair to its
home configuration.
Remote replication to the des-
tination is not allowed.
Remote replication from the
source is not allowed. Host
writes to the source continue
but are logged.
SourceSuspend remote replica-
tion in an asynchronous
mirror group pair.
Establishing a disaster recovery site
A Disaster Recovery (DR) site is a separate physical location in which you store alternative storage
equipment to be used if and when your main site equipment is lost due to an unforeseen event. Since
a DR site is usually established at a geographically remote location, the DR site cannot be connected
to the main site by Fibre Channel, but must be connected by the IP network. This means that data
must be sent between the sites over iSCSI. The iSCSI connection is suitable for transferring virtual disk
deltas after the initial copy of a virtual disk. The initial copy, however, is usually very large and takes
a long time to copy over iSCSI.
The following procedure enables you to set up asynchronous mirroring from your main site to your
DR site, but eliminates the performance penalty involved in using an iSCSI connection for the initial
build of your destination virtual disks. This procedure requires you to be able to bring your DR storage
equipment to your main site before you install the equipment at your DR site.
To establish a DR site with minimal performance penalty:
1. Temporarily install the DR storage equipment at the same site as your main storage equipment.
2. Bring the DR storage equipment under the management of a new SVSP domain. The SVSP domain
name and the computer names of the VSM server appliances must be set to their final value.
Contact HP services if this name must be changed.
3. Expose the main site's SVSP domain and the DR SVSP domain to each other over Fibre Channel.
4. Create async mirror groups to mirror the virtual disks on your main site to the DR SVSP domain.
5. Wait until the initial build of every destination virtual disk is complete.
6. Suspend the groups.
7. Disconnect the DR SVSP domain from the main site's SVSP domain. Each SVSP domain now
appears in the other SVSP domain with status absent.
8. Reinstall the DR SVSP domain at the DR site.
9. Establish connection between the SVSP domains over iSCSI. Verify that the SVSP domains once
again recognize each other.
10. Resume the async mirror tasks. The tasks now resynchronize and resume.
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