Volume Replicator 7.4.1 Administrator's Guide - Windows

To create the replicated data set

1. In the tree in the left pane, right-click the Replication Network node and select Setup Replicated Data Set.
2. Read the information about the Welcome panel and click Next.
3. Complete the Enter names for the Replicated Data Set and Replicated Volume Group panel as follows:

   Replicated Data Set name	Enter a name for the RDS.
   Replicated Volume Group name	Enter a name for the RVG. The same name is used for the Primary and Secondary RVG.
   Primary Host	By default the local host is selected. To specify a different host name, make sure that the required host is connected to the VEA console and select it in the Primary Host list. If the required host is not connected to the VEA, it does not appear in the list. In that case, use the VEA console to connect to the host.

   Click Next.

4. Select the dynamic disk group and volumes to be replicated as follows.

   Dynamic Disk Group

   Select the appropriate dynamic disk group from the list. Multiple disk groups cannot be added in an RDS.

   Select Volumes

   Choose the required data volumes from the table by selecting the check boxes for the volumes. To select all the volumes, select the check box in the top left corner of the Select Volumes table. To select multiple volumes, press the Shift or Control key while using the Up or Down arrow key. By default, adds DCM logs with mirrored plexes for all selected volumes. If the disk space is inadequate for creating a DCM with mirrored plexes, a single plex is created.

   Click Next.

5. Complete the Select or create a volume for Replicator Log panel by choosing one of the following:

   • To select an existing volume, select the volume in the table and click Next.

   • If you have not created a volume for the Replicator Log or want to create a new one, click Create Volume. Complete the information about the Create Volume dialog box as follows:

     Name	Enter a name for the volume.
     Size	Enter a size for the volume.
     Layout	Select the appropriate volume layout.
     Disks Selection	If you want Volume Replicator to select the disks for the Replicator Log, choose Select disks automatically. If you want to choose specific disks from the Available disks pane for the Replicator Log, choose Select disks manually. Either double-click on the disks or click Add to move the disks into the Selected disks pane.

     Click OK. The volume is created and displayed in the Replicator Log panel. Click Next. The summary panel appears.

6. Review the information on the summary panel. Click Back if you want to change any information.

   Click Create Primary RVG to create the RVG.

7. After the Primary RVG has been created successfully, Volume Replicator displays the following message:

   RDS with Primary RVG has been created successfully. Do you want
    to add Secondary host to this RDS for replication now?

8. On the Specify Secondary host for replication panel, enter the name or IP address of the Secondary host. Click Next. If the Secondary host is not connected to VEA, the wizard tries to connect it when you click Next. Wait till the connection process is complete and then click Next again.

   • If the disk group with the required data volumes and the Replicator Log volume as on the Primary host does not exist on the Secondary, Volume Replicator displays a message. Read the message carefully.

     • The option to automatically create the disk group and the associated volumes on the Secondary host is available only if the required number of disks of the same type, having the same or a larger amount of space as on the Primary, are available on the Secondary. Otherwise, the wizard enables you to create the disk group and the volumes manually.

     • Click Yes to automatically create the disk group, data volumes, and Replicator Log. Any available disks are automatically chosen for creating the disk group on the Secondary host.

     • Click No to manually create the disk group, data volumes, and Replicator Log. Complete the Create Dynamic Disk Group on Secondary host panel. If the dynamic disk group as on the Primary has already been created on the Secondary, then this panel does not appear.

       Complete the information on this panel as follows:

       Create cluster group	Choose this option only if you need to create clustered disk groups. Select the required disks from the Available disks pane. Either double-click on the disks or click Add to move the disks into the Selected disks pane. To select all the available disks, choose the Add All option.
       Create Dynamic Disk Group	Click Create Dynamic Disk Group to proceed with creating the disk group. A disk group with the same name as that on the Primary is created.

       After the disk group has been created, click Next. The Volume Information on connected hosts panel appears.

       Complete this panel as described in step 9.

   • If a disk group, without any data volumes or Replicator Log, as on the Primary host exists on the Secondary, Volume Replicator displays a message. Read the message carefully.

     • The option to automatically create the volumes on the Secondary host is available only as follows: If the disks that are part of the disk group have the same or a larger amount of space as on the Primary and enough space to create volumes with the same layout as on the Primary. Otherwise, the wizard enables you to create the required volumes manually.

     • Click Yes to automatically create the data volumes and the Replicator Log.

       After the configuration has been automatically created on the Secondary, proceed to step 10.

     • Click No to create the data volumes and the Replicator Log manually, using the Volume Information on connected hosts panel.

9. The Volume Information on connected hosts panel displays information about the availability of volumes on the Secondary nodes, if the Primary and Secondary hosts are connected to the VEA.

   This panel does not appear if all the required volumes that are available on the Primary host are also available on the Secondary hosts.

   If the required data volumes or the Replicator Log volume have not been created on the Secondary host, the panel displays the appropriate message against the volume name on the Secondary. Create the required volumes as follows:

   • For each required volume that is not created, click Create Volume.

   • The Create Volume dialog verifies the information about the Primary host and displays the volume name and the size.

     Complete the information on this panel as follows:

     Name	Displays the name that is specified for the Primary volume.
     Size	Displays the size that is specified for the primary volume.
     Layout	Lets you specify the volume layout. Select the appropriate volume layout depending on your requirement.
     Disks Selection	Enables you to specify the disk selection method. Select the Select disks automatically option if you want Volume Replicator to select the disks. Select the Select disks manually option to use specific disks from the Available disks pane for creating the volume. Either double-click on it or select Add to move the disks into the Selected disks pane.

     Click OK to create the required volume.

   • Repeat the steps for each of the data volumes and Replicator Log that has not been created.

   • After all volumes are created, the volume information panel is updated. Click Next.

   If the required volumes are created but are not eligible for replication, the reason for non-eligibility is indicated against the volume name.

   The Volume Information on connected hosts panel enables the appropriate option to convert a non-eligible volume to a Volume Replicator acceptable format.

   Complete the information on this panel as follows:

   Recreate Volume	This option is enabled if the required data volume is available on the Secondary, but is of a size greater than the Primary volume. Clicking this option displays a message that prompts you to confirm that you want to recreate the volume. Warning: This operation first deletes the volume resulting in loss of the data that already exists on the volumes. Choose Yes to recreate the volume using the Create Volume dialog.
   Remove DRL	This option is enabled if the required data volume is available on the Secondary but has a DRL. Clicking this option displays a message that prompts you to confirm that you want to remove the log. Click Yes to confirm the removal of DRL.
   Remove DCM	This option is enabled if the required Replicator Log volume is available on the Secondary but has a DCM log. Clicking this option displays a message that prompts you to confirm if you want to remove the log. Click Yes to confirm the removal of the DCM log.
   Expand Volume	This option is enabled if the required data volume is available on the Secondary but is of a smaller size than the Primary volume. Clicking this option displays a message that prompts you to confirm that you want to grow the volume. Click Yes to grow the volume to the required size.

   After you have converted the non-eligible volumes to a Volume Replicator acceptable format, click Next.

   If the volume on the Secondary is already a part of another RDS, the wizard does not let you proceed. If you want to use the same volume, you must either remove the corresponding Primary volume from the Primary RVG or delete the other RDS.

10. Complete the Edit replication settings panel to specify basic and advanced replication settings for a Secondary host as follows:

    • To modify the default values for the basic settings, select the required value from the drop-down list for each property, as follows:

      Primary side IP	Displays the IP address on the Primary that is to be used for replication. If there is more than one IP address available for replication, you can choose the one that you want to use from the drop-down list. If the required IP address is not displayed in the list, edit the field to add the IP address.
      Secondary Side IP	Displays the IP address on the Secondary that is to be used for replication, if the Secondary is connected to VEA. If there is more than one IP address available for replication, you can choose the one that you want to use from the drop-down list. If the required IP address is not displayed in the list, edit the field to add the IP address.
      Replication Mode	Select the required mode of replication; Synchronous, Asynchronous, or Synchronous Override. The default is synchronous override. Note: If the Secondary is set to the synchronous mode of replication and is disconnected, the Primary data volumes with NTFS or ReFS file systems may be displayed as MISSING.
      Replicator Log Protection	The AutoDCM is the default 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 DCM option enables the Replicator Log protection for the Secondary host when the Replicator Log overflows, and the connection between the Primary and Secondary is lost. This option is available only if all the data volumes under the Primary RVG have a DCM Log associated with them. The Off option disables Replicator Log Overflow protection. In the case of the Bunker node. Replicator Log protection is set to Off, by default. Thus, if the Primary RLINK overflows due to the Bunker RLINK, then this RLINK is detached. The Override option enables log protection. If the Secondary node is still connected and the Replicator Log is about to overflow, the writes are stalled until 5% or 20 MB of space (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 5% or 20 MB of space (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	This option enables you to specify a Primary RLINK name of your choice. If you do not specify any name, Volume Replicator assigns a default name.
      Secondary RLINK Name	This option enables you to specify a Secondary RLINK name of your choice. If you do not specify any name, Volume Replicator assigns a default name.

    • To proceed without modifying the advanced replication settings, click Next. The Start Replication panel appears.

      Proceed to step 11.

    • To specify advanced replication settings, click Advanced.

      Complete the Advanced Replication Settings panel as follows:

      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. The 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 can be behind the Primary. The default value is 10000, but you can specify the required limit. 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 Primary continue to be stalled until the number of pending updates on the Replicator Log falls back to the Low Mark Value. The default value is 9950, but you can specify the required limit.
      Protocol	UDP/IP is the default replication protocol. Choose TCP/IP or UDP/IP for a regular Secondary. If the storage on the Bunker Secondary is directly accessible from the Primary use the STORAGE protocol, otherwise use TCP/IP or UDP/IP. Note: If the replication protocol for the Bunker Secondary has been set to STORAGE, you can change it only by deleting and recreating the Bunker with the required protocol; UDP/IP or TCP/IP. You cannot change the STORAGE protocol using the Change Replication Settings option.
      Packet Size(Bytes)	Default is 1400. Choose the required packet size for data transfer from the drop-down list. The default unit for the packet size is Bytes. You can set the packet size only if the protocol is UDP/IP. Some firewalls do not support packet sizes greater than 1400 bytes. To replicate across such a firewall, use the default packet size to make sure all the Volume Replicator operations function as required. You can also set the packet size to 1300 by selecting from the list. The minimum packet size that you can specify is 1100 bytes. Note: If you need to set a value for packet size different from the value that is provided in the list, use the command line interface.
      Bandwidth	By default, Volume Replicator uses the maximum available bandwidth. To control the bandwidth thatVolume Replicator uses for replication, choose Specify Limit, and then specify the bandwidth limit in the field provided. The default unit is Megabits per second (Mbps) and the minimum allowed value is 1 Mbps.
      Enable Compression	Enable this option if you want to enable compression for the Secondary host.

      After completing the Advanced Replication Settings panel, click OK. The wizard returns to the Edit Replication Settings panel. Click Next. The Start Replication panel appears.

11. Choose the appropriate option from the Start Replication panel as follows:

    • To add the Secondary and start replication immediately, select the Start Replication with one of the following options:

      Synchronize Automatically

      For an initial setup, use this option to synchronize the Secondary and start the replication. This setting is the default. When this option is selected, Volume Replicator by default performs intelligent synchronization to replicate only those blocks on a volume that the file system uses. If required, you can disable intelligent synchronization. Note: Intelligent synchronization is applicable only to volumes with the NTFS and ReFS file systems and not to raw volumes or volumes with FAT file systems.

      Synchronize from Checkpoint

      If you want to use this method, then you must first create a checkpoint. If the Primary data volumes have a considerable amount of data, 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 checkpoint; this operation synchronizes the Secondary with the writes that happened when backup-restore was in progress.

    • To add the Secondary without starting replication, deselect the Start Replication option. You can start replication later by using the Start Replication option from the Secondary RVG right-click menu.

      Click Next to display the Summary panel.

12. Review the information on the Summary panel.

    Click Back to change any information you had specified or click Finish to add the Secondary to the RDS and exit the wizard.