Administrator Guide

Activating Disaster Recovery
Activate DR when a volume or site becomes unavailable. When DR is activated, a view volume of the original destination volume
(replication) or secondary volume (Live Volume) is brought on line and mapped to a server at the DR site. Before DR can be activated for
a volume, at least one snapshot must have been Replicated to the DR site.
Types of Disaster Recovery Activation for Live Volumes
Storage Center supports two types of Disaster Recovery for Live Volumes:
• Preserve Live Volume: Directs IO requests to the secondary volume by promoting it to primary. The Live Volume is not deleted and
may be repaired when an administrator restores the volume after the source Storage Center comes back online. Volume identity is
preserved so that administrator intervention is not required on the servers mapped to the volume. If a replication is managed by the
Live Volume, the managed replication is preserved and follows the DR-activated volume.
• Recreate Live Volume: If Preserve Live Volume is not selected or not available, Storage Manager deletes the Live Volume, creates
a view volume, and maps it to a server. During the recovery process, the Live Volume is recreated. If a replication is managed by the
Live Volume, the managed replication is removed during the recovery process.
Disaster Recovery Activation Limitations
Activating DR for a replication removes any replications that use the activated volume (original destination/secondary volume) as the
source volume.
Related concepts
Replicating a Single Volume to Multiple Destinations
Related information
Planned vs Unplanned Disaster Recovery Activation
During disaster recovery activation, you may choose whether you want to allow planned DR activation. The following table displays some
of the differences between planned and unplanned DR activation.
Planned DR Activation
Unplanned DR Activation
The servers on the production site are shut down. The servers on the production site are not shut down.
The Storage Centers on the production site do not have to be shut
down.
The Storage Centers on the production site are shut down.
The source volume is no longer mapped to the server. The source volume is still mapped to the production servers.
You can copy any remaining data prior to activation, eliminating
data loss.
Data may be lost, depending on the recovery point objective
(RPO).
The production site will not come back online while service has
switched to the DR site.
The production Storage Centers and the servers may come back
online, creating the danger of a split brain.
Disaster Recovery Activation Procedures
If an entire site becomes unavailable, DR can be activated for all affected volumes in a single operation. If a single volume becomes
unavailable, activate DR for the corresponding restore point.
Storage Center DR Preparation and Activation
519