VERITAS Cluster Server
For replication in a clustered system, note the following points that do not apply to regular operation:
If failover occurs while running a replication command, you must ensure consistency by using swsrprecoverres (Resource adjustment command) as a recovery measure.
When you use synchronous replication, do not register any destination volumes to a cluster transaction.
You must perform replication on the active system of the service groups because AdvancedCopy Manager is placed in the service groups and operates as a part of it.
You cannot perform replication from a standby node or another service group.
To perform replication, you must unmount original/source volumes beforehand and mount the volumes later for some commands.
If the mount points of original/source volumes have been registered to a cluster transaction, set the mount point resources online or offline from the cluster transaction instead of mounting or unmounting the volumes. Alternatively, modify the unmount and mount processes in the replication pre-processing and post-processing scripts to offline and online processes, respectively.
Moreover, the Volume is immediately placed offline/online for a mount point resource whereas there will be a time delay when mount/unmount is used. Therefore, please add into the pre-processing script, after the statement where the success or failure value of offline/online is returned, the df or sleep command to function until mount/unmount is actually complete.
For details and examples on the types of commands that require the volumes to be unmounted and mounted, and the pre-processing and post-processing scripts, refer to "Appendix C Pre-processing and Post-processing of Replication". For details on the commands used to set resources online and offline, refer to the relevant clustered system manual.
VERITAS Cluster Server
When a service group to which AdvancedCopy Manager belongs is operating, replication is enabled only on the active node. The standby node environment is not ready (to provide necessary resources) for replication, and replication is, therefore, disabled. Likewise, if the service group has been stopped, the environment is not ready and disables replication.
However, replication is temporarily enabled when the service group has been stopped.
Note
If any of the following types of shared disks cannot be enabled (i.e., set online or mounted in a system), replication is disabled.
Shared disk for AdvancedCopy Manager shared data
Replication operation disks (source volume/destination volume to operate)
The following operations are not allowed in replication:
Manipulation for replication from a Management Server (host specification with the -h option)
Addition or deletion of an original/replica volume
Inter-server replication without the -m option specified
To execute a display command for replication management to a Management Server transaction that also functions as a Managed Server transaction, you must specify options for the command. For details on the display command for replication management, refer to "8.4 Replication Management Commands".
Perform replication during stoppage of the service group by taking the steps below.
Confirm that the service group has been stopped on both nodes.
For details on how to stop a service group, refer to the VERITAS Cluster Server manual.
Log in (for example, through Telnet) to the node on which you want to perform replication.
You cannot use the logical IP address. Use a node that is operable via the physical IP address.
Enable the shared disk.
Start (set online) the shared disk.
Mount the shared disk for AdvancedCopy Manager shared data.
When the original volume and replica volume have been mounted as file systems for operation, mount the volumes.
Note
Be sure to enable the shared disk from either node. Do not enable the shared disk from both nodes.
In the SWSTGNODE environment variable, set the logical node name for the relevant task.
Set the environment variable as shown below.
<Execution example>
# SWSTGNODE=logical-node-name # export SWSTGNODE |
Perform replication.
You can perform replication in the same way as for regular operations in a cluster environment.
You can also perform restoration from the replica volume to the original volume.
Release all the shared disks you enabled in Step 3.
Unmount the file systems you mounted.
Stop (set offline) the shared disk.
Start (set online) the service group.
Start the service group, if necessary.
For details on how to start a service group, refer to the VERITAS Cluster Server manual.
