Following on from the EMC Unity Setup Guide and EMC Unity Configuration Guide, we will walk through setting up replication between 2 Unity arrays. For Remote Office and Branch Offices replication can be configured between the Unity VSA and a physical Unity array in the datacentre.
Replication between storage devices provides data redundancy and protects against storage system failures. EMC Unity provides synchronous or asynchronous replication; synchronous replication is only available to physical arrays and can protect LUNs, Consistency Groups, and VMware VMFS datastores. Asynchronous replication is applicable to all products in the Unity range and can protect the storage resources listed previously, as well as File Systems, NAS Servers, and VMware NFS datastores. Replication can be configured within the same system or to a different system locally, or in a remote location. All EMC Unity systems are licensed for replication as standard. For more information on EMC Unity replication technologies see the Unity Replication White Paper.
Establishing Replication Connections
Before configuring replication a secure link between Unity systems must be established. All tasks are carried out using the HTML5 Unisphere web client. Browse to the IP or FQDN of either Unity system.
Under Data Protection on the left hand navigation pane select Replication. First we need to configure the interfaces to use for replication traffic, so click the Interfaces tab.
Click the plus symbol (Create Replication Interface). Select the interface to use on each storage processor, if you have created link aggregation groups these are also listed. For assistance with creating link aggregation groups see the EMC Unity Configuration Guide. Enter the IP address to use for replication traffic for each storage processor, configure a VLAN ID if required, and click Ok.
The created replication interfaces will now be listed, you can also edit and delete replication interfaces from this tab. You need to configure the replication interfaces on both the source and destination system.
Next we setup a remote connection between the storage systems. From either device select the Connections tab.
Enter the management IP address and credentials of the remote system, and the admin password for the local system. Select the replication type; in this example we will use Asynchronous. Click Ok.
A replication connection will now be established on both the local and remote systems. Once complete click Close.
Select the storage resource to configure replication, in this post we will replicate a file system. The NAS Server hosting the file system must be configured for replication. Browse to File under the Storage menu, open the NAS Servers tab and select the NAS server to replicate. Click Edit and select the Replication tab.
Select the replication mode and RPO (Recovery Point Objective) time. The replication destination is the remote system connection we established earlier. Click Next.
Select the storage pool and storage processor for the destination storage system, the NAS Server name will auto-populate. Any existing file systems stored on the NAS Server will be listed for replication. Click Next.
Review the summary page and click Finish and Close.
When creating new file systems they can be configured for replication on the Replication page of the create a file system wizard.
A destination file system is automatically created on the destination storage system.
Alternatively we can configure replication at a later date. To do this open the File Systems tab and select the file system to replicate, click Edit.
Select the Replication tab. Click Configure Replication.
The replication wizard will open. The replication session inherits the configuration from the NAS Server. Click Next.
A file system on the destination file system will automatically be created. Select the storage pool to use on the destination storage system, click Next.
Review the summary page and click Finish. The replication session will be established, once complete click Close.
We can confirm the replication status by going back into the properties of the file system and the Replication tab where the replication status will be displayed. The replication role of the file system on the source storage system is Source, on the remote system the file system role is Destination. We can also go back to the Replication page and open Sessions. The replication sessions will be listed.