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 specic 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 Conguration
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 modies 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 64. Live Volume with Managed Replication Example Conguration
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)
552 Storage Center Replications and Live Volumes