This operation should be started on the Primary Server to the Secondary Server from the Edit menu or initiated automatically upon completing the Create Resource Hierarchy option in which case you should refer to Step 2 below.

  1. On the Edit menu, select Resource then Extend Resource Hierarchy. The Pre-Extend Wizard appears. If you are unfamiliar with the Extend operation, click Next. If you are familiar with the LifeKeeper Extend Resource Hierarchy defaults and want to bypass the prompts for input/confirmation, click Accept Defaults.
  1. The Pre-Extend Wizard will prompt you to enter the following information.

Note: The first two fields appear only if you initiated the Extend from the Edit menu.

Field
Tips
Template Server

Select the Template Server where your DataKeeper resource hierarchy is currently in service. It is important to remember that the Template Server you select now and the Tag to Extend that you select in the next dialog box represent an in-service (activated) resource hierarchy.

An error message will appear if you select a resource tag that is not in service on the template server you have selected. The drop down box in this dialog provides the names of all the servers in your cluster.

Tag to Extend This is the name of the DataKeeper instance you wish to extend from the template server to the target server. The drop down box will list all the resources that you have created on the template server.
Target Server Enter or select the server you are extending to.
Switchback Type

You must select intelligent switchback. This means that after a failover to the backup server, an administrator must manually switch the Multi-Site Cluster hierarchy resource back to the primary server.

CAUTION: This release of DataKeeper for Linux does not support Automatic Switchback for DataKeeper resources. Additionally, the Automatic Switchback restriction is applicable for any other LifeKeeper resource that becomes part of the Multi-Site Cluster hierarchy. This includes anything sitting above the hierarchy or becomes a child within the hierarchy.

Template Priority

Select or enter a Template Priority. This is the priority for the DataKeeper hierarchy on the server where it is currently in service. Any unused priority value from 1 to 999 is valid, where a lower number means a higher priority (1=highest). The extend process will reject any priority for this hierarchy that is already in use by another system. The default value is recommended.

Note: This selection will appear only for the initial extend of the hierarchy.

Target Priority Select or enter the Target Priority. This is the priority for the new extended DataKeeper hierarchy relative to equivalent hierarchies on other servers. Any unused priority value from 1 to 999 is valid, indicating a server’s priority in the cascading failover sequence for the resource. A lower number means a higher priority (1=highest). Note that LifeKeeper assigns the number “1” to the server on which the hierarchy is created by default. The priorities need not be consecutive, but no two servers can have the same priority for a given resource.
  1. After receiving the message that the pre-extend checks were successful, click Next.
  1. Depending upon the hierarchy being extended, LifeKeeper will display a series of information boxes showing the Resource Tags to be extended, some of which cannot be edited.

Click Next to launch the Extend Resource Hierarchy configuration task.

The next section lists the steps required to complete the extension of a DataKeeper resource to another server.

Extending a DataKeeper Resource

  1. After you have been notified that your pre-extend script has executed successfully, you will be prompted for the following information:
Field
Tips
Mount Point Enter the name of the file system mount point on the target server. (This dialog will not appear if there is no LifeKeeper-protected filesystem associated with the DataKeeper Resource.)
Root Tag Select or enter the Root Tag. This is a unique name for the filesystem resource instance on the target server. (This dialog will not appear if there is no LifeKeeper-protected filesystem associated with the DataKeeper Resource.)
DataKeeper Resource Tag

Select or enter the DataKeeper Resource Tag name.

Bitmap File

Select the name of the bitmap file used for intent logging. If you choose None, then an intent log will not be used and every resynchronization will be a full resync instead of a partial resync.

Important: The bitmap file should not reside on a btrfs filesystem. Placing data replication bitmap files on a btrfs filesystem will result in an “invalid argument” error when LifeKeeper tries to configure the mirror. The default location for the bitmap file is under /opt/LifeKeeper. This default location should be changed if /opt/LifeKeeper resides on a btrfs filesystem.

  1. Click Next to continue. An information box will appear verifying that the extension is being performed.
  1. Click Finish to confirm the successful extension of your DataKeeper resource instance.
  1. Click Done to exit the Extend Resources Hierarchy menu selection.

Note: Be sure to test the functionality of the new instance on all servers by performing a manual switchover. See Testing Your Resource Hierarchy for details. At this point, DataKeeper has initiated the data resynchronization from the source to the target disk or partition. In the LifeKeeper GUI, the state of the DataKeeper resource on the target server is set to “Resyncing”. Once the resynchronization is complete, the state will change to “Target” which is the normal Standby condition.

During resynchronization, the DataKeeper resource and any resource that depends on it will not be able to fail over. This is to avoid data corruption.

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