Administrator Guide

Managed Replications for Live Volumes
A managed replication allows you to replicate a primary Live Volume to a third Storage Center, protecting against data loss in the event
that the site where the primary and secondary Storage Centers are located goes down. When a Live Volume swap role occurs, the
managed replication follows the primary volume to the other Storage Center.
Supported Live Volume with Managed Replication Topologies
Three specific combinations of Live Volume type and managed replication type are supported. The following table lists the supported
combinations.
Live Volume Type Managed Replication Type
Asynchronous Synchronous
Asynchronous Asynchronous
Synchronous Asynchronous
Live Volume with Managed Replication Example Configuration
The following examples show how a managed replication behaves before and after a Live Volume swap role.
• Live Volume behavior: When a server near the primary Storage Center sends an IO request that modifies the primary volume, the
changes to the primary Live Volume are replicated to the secondary Storage Center over Fibre Channel or iSCSI. When a server near
the secondary Storage Center sends an IO request to the secondary Live Volume, the secondary Storage Center forwards the IO
request to the primary volume on the primary Storage Center. These changes to the primary volume are ultimately replicated to the
secondary volume.
• Managed replication behavior: The changes to the primary Live Volume are replicated to the third Storage Center over Fibre
Channel or iSCSI. When a Live Volume swap role occurs, the managed replication follows the primary volume to the other Storage
Center.
Managed Replication Before Live Volume Swap Role
In the following diagram, the primary Storage Center is on the left and the secondary Storage Center is located on the right.
Figure 53. Live Volume with Managed Replication Example Configuration
1.
Server 2. Server IO request to primary volume over Fibre Channel or iSCSI
3. Primary volume (Live Volume and managed replication) 4. Live Volume replication over Fibre Channel or iSCSI
5. Secondary volume (Live Volume) 6. Server IO request to secondary volume (forwarded to primary
Storage Center by secondary Storage Center)
7. Server 8. Destination volume (managed replication)
9. Managed replication over Fibre Channel or iSCSI
498 Storage Center Replications and Live Volumes