Storage Foundation and High Availability Solutions 7.4.2 Solutions Guide - Windows

To configure Volume Replicator replication and GCO

1. Verify that the application server service group is online at the primary site and the appropriate disk groups are imported at the secondary site.
2. If the DR wizard is still open after the previous wizard task, continue with the Replication Setup panel.

   Otherwise, launch the wizard and proceed to the Replication Setup panel as follows:

   • Start the Solutions Configuration Center from the Apps menu on the Start screen.

   • Expand the Solutions for Additional Applications tab and click Disaster Recovery Configuration > Configure Disaster Recovery > Disaster Recovery Configuration Wizard.

3. On the Welcome panel, click Next and continue through the wizard, providing the requested information.
4. On the Replication Methods panel, click Configure Volume Replicator and the Global Cluster Option (GCO). Click Next.
5. In the Internet Protocol panel, select IPv4 or IPv6 depending on which type of network you are using. (You must use the same on primary and secondary sites.) Click Next.
6. In the Replication Setup panel, review the replication requirements. If you have met the requirements, click Next. If not, click Cancel and restart the wizard after meeting the requirements.
7. In the Replication Settings for Replicated Volume Group panel, specify the requested information. If you are adding a DR site to an existing DR configuration, fields that must match the existing settings, such as the RVG or RDS name, are dimmed so that you cannot change them.

   Disk Group	The left column lists the disk groups. By design, an RVG is created for each disk group.
   RVG Name	Displays the default RVG name. If required, change this to a name of your choice.
   RDS Name	Displays the default Replicated Data Set (RDS) name. If required, change this to a name of your choice.
   Available Volumes	Displays the list of available volumes that have not been selected to be a part of the RVG. Either double-click on the volume name or use the > button to move the volumes into the Selected RVG Volumes pane.
   Selected RVG Volumes	Displays the list of volumes that have been selected to be a part of the RVG. To remove a selected volume, either double-click the volume name or use the < button to move the volumes into the Available Volumes pane.
   Primary SRL	If you did not create a Replicator Log volume on the primary site, click Create New on the drop-down menu. On the New Volume dialog box, specify the name, size, and disk. Otherwise, select the appropriate primary Replicator Log volume from the drop-down menu and enter an appropriate size.
   Secondary SRL	If you did not create a Replicator Log volume on the primary site, click Create New on the drop-down menu. On the New Volume dialog box, specify the same name and size as you specified for the primary SRL. Otherwise, select the appropriate secondary Replicator Log volume from the drop-down menu and enter an appropriate size.
   Add RVG	Click this option to create a new RVG. This option is especially useful if you want to organize the volumes present in a disk group under separate RVGs. By default, the wizard is designed to organize all the volumes under a disk group under one RVG. However, you can use the Add RVG option to organize them differently, based on your specific requirements.
   Delete RVG	Click this option to delete any of the existing RVGs related to the DR set up that you are creating.
   Start Replication after the wizard completes	Select this check box to start replication automatically after the wizard completes the necessary configurations. Once replication is configured and running, deselecting the checkbox does not stop replication.

   Click Advanced Settings to specify some additional replication properties.

   

   The options on the dialog box are described column-wise, from left to right:

   Replication Mode	Select the required mode of replication; Synchronous, Asynchronous, or Synchronous Override (default).
   Log Protection	Select the appropriate log protection from the list: AutoDCM is the default selected mode for the Replicator Log overflow protection when all the volumes in the Primary RVG have a DCM log. The DCM is enabled when the Replicator Log overflows. The Off option disables Replicator Log Overflow protection. The Override option enables log protection. If the Secondary node is still connected and the Replicator Log is about to overflow then the writes are stalled until a predetermined amount of space, that is, 5% or 20 MB (whichever is lesser) becomes available in the Replicator Log. If the Secondary becomes inactive due to disconnection or administrative action then Replicator log protection is disabled, and the Replicator Log overflows. The Fail option enables log protection. If the log is about to overflow the writes are stalled until a predetermined amount of space, that is, 5% or 20 MB (whichever is lesser) becomes available in the Replicator Log. If the connection between primary and secondary RVG is broken, then, any new writes to the primary RVG are failed.
   Primary RLINK Name	Enter a name of your choice for the primary RLINK. If you do not specify any name then the wizard assigns a default name.
   Secondary RLINK Name	Enter a name of your choice for the Secondary RLINK. If you do not specify any name then the wizard assigns a default name.
   Bandwidth	By default, Volume Replicator replication uses the maximum available bandwidth. You can select Specify to specify a bandwidth limit. The default unit is Megabits per second (Mbps) and the minimum allowed value is 1 Mbps.
   Protocol	Choose TCP or UDP. UDP/IP is the default replication protocol.
   Packet Size (Bytes)	Default is 1400 Bytes. From the drop-down list, choose the required packet size for data transfer. The default unit for the packet size is Bytes. You can set the packet size only if the protocol is UDP/IP.
   Latency Protection	By default, latency protection is set to Off. When this option is selected the High Mark Value and the Low Mark Value are disabled. Select the Fail or Override option to enable Latency protection. This Override option behaves like the Off option when the Secondary is disconnected and behaves like the Fail option when the Secondary is connected.
   High Mark Value	This option is enabled only when Latency Protection is set to Override or Fail. It specifies the maximum number of pending updates by which the secondary site can be behind the primary site. The default value is 10000. To ensure that latency protection is most effective the difference between the high and low mark values must not be very large.
   Low Mark Value	This option is enabled only when Latency Protection is set to Override or Fail. When the updates in the Replicator log reach the High Mark Value, then the writes to the system at the primary site continues to be stalled until the number of pending updates on the Replicator log falls back to the Low Mark Value. The default is 9950.
   Initial Synchronization	If you are doing an initial setup, then use the Auto Synchronous option to synchronize the secondary site and start replication. This is the default. When this option is selected, Volume Replicator by default performs intelligent synchronization to replicate only those blocks on a volume that are being used by the file system. If required, you can disable intelligent synchronization. If you want to use the Synchronize from Checkpoint method then you must first create a checkpoint. If you have a considerable amount of data on the primary data volumes then you may first want to synchronize the secondary for existing data using the backup-restore method with checkpoint. After the restore is complete, use the Synchronize from Checkpoint option to start replication from the checkpoint to synchronize the secondary with the writes that happened when backup-restore was in progress.

   To apply changes to advanced settings, click OK.

   For additional information on Volume Replicator replication options, refer to the Volume Replicator Administrator's Guide.

   Click Next.

8. In the Replication Attribute Settings panel, specify required replication attribute information for the cluster at the primary and secondary site. Click the arrow icon to expand an RVG row and display the replication attribute fields. If you are configuring an additional secondary site (multiple DR sites), some fields are disabled.

   Disk Group	Displays the list of disk groups that have been configured.
   RVG Name	Displays the Replicated Volume Groups corresponding to the disk groups.
   IP Address	For IPv4 networks, enter replication IPs that will be used for replication, one for the primary site and another for the secondary site. For IPv6, select the network from the dropdown list. An IP address will be generated.
   Subnet Mask or Prefix	For IPv4, enter the subnet mask for the system at the primary site and the secondary site. For IPv6, enter the prefix.
   Public NIC	Select the public NIC from the drop-down list for the system at the primary and secondary site. For IPv6, available NICs are those belonging to the selected network.
   Copy	Enables you to copy the above network settings to any additional RVGs that are listed on this screen. If there is only one RVG, this option does not apply.

   After specifying the replication attributes for each of the RVGs, click Next.

9. In the Global Cluster Settings panel specify the heartbeat information for the wide-area connector resource. You must specify this information for the primary and the secondary cluster. Any existing WAC resource information can be reused. If you are adding a DR site to an existing DR configuration, GCO is already configured at the primary site, so the primary site fields are dimmed.

   Use existing settings	Allows you to use a WAC resource that already exists at either the primary or secondary site. Click Primary or Secondary, depending on the site at which the WAC resource already exists.
   Resource Name	Select the existing WAC resource name from the resource name list box.
   Create new settings	Select the appropriate site, primary or secondary, for which you want to create a new WAC resource.
   IP Address	For IPv4, enter a virtual IP for the WAC resource. For IPv6, select the network from the dropdown list. An IP address will be generated.
   Subnet Mask or Prefix	For IPv4, enter the subnet mask for the system at the primary site and the secondary site. For IPv6, enter the prefix.
   Public NIC	Select the public NIC for each system from the drop-down list for the system at the primary and secondary site.
   Start GCO after configuration	Select this check box to bring the cluster service group online and start GCO automatically after the wizard completes the necessary configurations. Otherwise, you must bring the service group online and start GCO manually, after the wizard completes. Once GCO is configured and running, deselecting the checkbox does not stop GCO.

10. In the Settings Summary panel, review the displayed information.

    Click Back if you want to change any of the parameters. If you have a printer installed, you can click the printer icon at the bottom of the scrollable list to print the settings.

    Otherwise, click Next to implement the settings.

11. In the Implementation panel, wait till the wizard completes creating the replication configuration and the WAC resource required for global clustering. If a task could not be completed successfully, it is marked with an (x) symbol. For any critical errors, the wizard displays an error message. For less critical errors, the Information column displays a brief description about the task failure and the next screen displays additional information on what action you can take to remedy it. Click Next.
12. In the Finish panel, review the displayed information. If a task did not complete successfully, the panel displays an error message, which will provide some insight into the cause for failure. Click Finish to exit the wizard.