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ETERNUS SF AdvancedCopy Manager 14.2 Operator's Guide

10.1.8 Notes on replication in a cluster system

MC/ServiceGuard

For replication in a cluster system, note the following points that do not apply to regular operation:

In addition, if the destination volume belongs to a volume group and failover occurs while synchronization (EC/REC) is being handled, package startup is disabled because the destination volume cannot be activated on the standby node.
Therefore, in a cluster environment you should use OPC based, snapshot type replications.
If package startup is disabled during EC-based synchronous replication, forcibly stop the synchronization by using ETERNUS Web GUI or similar, and then start the package.

VERITAS Cluster Server

For replication in a cluster system, note the following points that do not apply to regular operation:

10.1.8.1 Replication during the stoppage of a cluster

MC/ServiceGuard

When the package to which AdvancedCopy Manager belongs is operating, replication is enabled only on the active node. The standby node environment is not ready to provide the necessary resources, thus disabling replication. Likewise, if the package has been stopped, the environment is not ready and it disables replication.
However, replication is re-enabled only when the package has been stopped, by temporarily arranging the minimum essential resources.

Note

  • If either 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 disks (source volume/destination volume to operate)

  • The following are not allowed in replication operations:

    • Manipulation for replication from a Storage Management Server (host specification with the "-h" option)

    • Addition or deletion of an original/replica volume

    • Inter-server replication without the "-m" option specified

  • Command options must be specified if replication management display commands are executed for Storage Management Server transactions in conjunction with Storage Server transactions. Refer to "swsrprecoverres (Resource adjustment command)" for information concerning the replication management display commands.

Perform replication during stoppage of a package by taking the following steps:

  1. Confirm that the package has been stopped on both nodes.
    For details on how to stop the package, see the MC/ServiceGuard manual.

  2. Log in to the node on which you want to perform replication, for example through telnet.
    You cannot use the logical IP address. Directly use a node that is accessible via the physical IP address.

  3. 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.

  4. 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
  5. Perform the replication.

    You can perform the replication in the same way as for regular cluster operations.

  6. Release all the shared disks you enabled in Step 3.

    Unmount the file systems you mounted.

    Stop (set offline) the shared disk.

  7. Start (set online) the package.

    Start the package, if necessary.

    For details on how to start the package, see the MC/ServiceGuard 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 Storage 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 Storage Management Server transaction that also functions as a Storage Server transaction, you must specify options for the command. For details on the display command for replication management, see "9.4 Replication Management Commands".

Perform replication during stoppage of the service group by taking the steps below.

  1. Confirm that the service group has been stopped on both nodes.
    For details on how to stop a service group, see the VERITAS Cluster Server manual.

  2. 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.

  3. 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.

  4. 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
  5. 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.

  6. Release all the shared disks you enabled in Step 3.
    Unmount the file systems you mounted.
    Stop (set offline) the shared disk.

  7. Start (set online) the service group.
    Start the service group, if necessary.
    For details on how to start a service group, see the VERITAS Cluster Server manual.