Configuring tertiary replication targets

Replication and Disaster Recovery Administration Guide for Hitachi NAS Platform

Version
15.1.x
Audience
anonymous
Part Number
MK-92HNAS009-29

Tertiary replication targets are configured using the Object Replication page of the NAS Manager. This procedure enables you to configure an additional (tertiary) replication target using an existing replication target as the source.

Definitions

  • Primary - the original data source
  • Secondary - the first replication target
  • Tertiary - the final replication target

Pre-requisites

This procedure requires an existing (primary to secondary) replication policy which uses manual snapshot rules at both ends. Ensure that a snapshot has been created using the rule on the source and that at least one replication has completed using the policy before starting this procedure. Automatic snapshot rules are not supported with tertiary replication.

  1. Navigate to Home > Data Protection > Object Replication, and click add to open the Add Object Replication Policy page.


    The following table describes the fields on this page:

    Field/Item Description
    Identification
    Name The name of the object replication policy.
    Source
    EVS/file system The name of the source EVS and file system that is to be replicated to the object replication target. To change the source EVS/file system, click changeā€¦.
    EVS IP Address The default value for this field is 'Automatically selected'. If required, select the IP address for the source EVS from the list.
    Target
    Server Select a server from the list to be the target of the object replication policy. After selecting a server, click select a target... to select an EVS and file system. For managed servers, the EVS Name and File System fields are automatically populated when you select a file system using select a target... Or, alternatively, type the EVS IP/host name and file system name in the corresponding fields.
    EVS DNS Name or IP Select the EVS IP/host name in this field.
    EVS IP Address Enter the EVS IP address in this field.
    File System Select the target file system of the object replication policy. If the replication process is not managing the server on which the target file system is hosted, or if the destination file system does not yet exist, select Specify EVS IP/host name and file system from the list and type the details in the appropriate fields.
    Note: The replication target file system should be at least as large as the source file system to ensure that all data can be replicated on the target. If you intend to keep multiple snapshots on the target, it is especially important that the target be larger than the source, because the additional snapshots on the target file system will require storage space.
    Note: The tiering of both the replication source and target file systems must agree; you cannot have a tiered source file system replicated to an untiered file system, and you cannot have an untiered source file system replicated to a tiered file system.
    Object Replication Listening Port The port on which the destination server is listening. The default is 59550. The port on which the destination server listens is configured on the Object Replication Configuration page of the NAS Manager, or through the replication-listening-port CLI command.
    Note: To change the listening port for the target server, you must make that server the currently managed server of the replication process, then use the Object Replication Configuration page of the NAS Manager to change the listening port.
  2. In the Identification section, enter a name for the replication policy in the Name field.
  3. In the Source section, select the secondary EVS/File System and the EVS IP Address.
  4. In the Target section, select the tertiary server from the Server drop down list.
  5. Click the select a target button. Use the Select a File System drop down menu to select the file system/EVS that you want to use as the tertiary replication target.
    The File System field of the Target section now shows the selected file system. Click Next.



  6. If access point transfer was not enabled on the source file system (or set during a replication policy creation), an information page appears which explains that the source file system is not configured to allow its access points to be transferred with an object replication. For the tertiary policy, no action is necessary. Click Continue.


  7. You are now prompted to select the snapshot rules to be used by the source (secondary) and target (tertiary) file systems. Check the Use Snapshot rule buttons in the Processing Options section and select a manual snapshot rule for both the source and the target. Click Next.


    Warning: Never use automatic snapshot rules when setting up secondary to tertiary targets. When using multiple replications in a chain, a snapshot of the source is not automatically propagated to the secondary and tertiary targets at the same time. While the replication from primary to secondary is underway, the snapshots on the tertiary do not yet reflect the source. Once the primary to secondary replication is complete, and the subsequent secondary to tertiary replication is complete, at that point the snapshots on the three file systems will match, but not before. If an updated snapshot appears in a rule during replication, this snapshot is not used until the next scheduled replication. If you are uncertain on how to proceed, it is recommended that you consult with your Hitachi Vantara technical support representative.
  8. If you haven't yet created an initial snapshot for the selected manual rule, an information page appears which explains that a baseline snapshot could not be established. Click Continue and then OK. After completing the setup of this policy, run a manual snapshot between the primary source and secondary target.


  9. A summary page appears containing the details of the tertiary object replication policy. Click create to confirm the creation of the policy.

  10. A message appears explaining that the policy has been successfully created. You are now prompted to create a policy schedule for the new policy. You can proceed without creating a schedule at this time, but note that you must use policy schedules when using the tertiary target for disaster recovery. You can create schedules later. If you want to create one now, click yes to create a policy schedule. For detailed information on schedules, see the sections Using object replication policies and Using object replication schedules in this guide.


    Click no to return to the Object Replication page.
  11. On the Object replication page, run and test the new replication policies as described in the example below. You can run the replications manually, without policy schedules.


    Test and run the primary to secondary replication. After the policy has run successfully, the icon in the Status column is green and the status shows as "Complete".



    Test and run the secondary to tertiary replication. After the replication has run successfully, both icons in the Status column are green.