Disaster Tolerance and Recovery in a Serviceguard Cluster
Understanding Types of Disaster Tolerant Clusters
Also note that the networking in the configuration shown is the minimum. Added network connections for additional heartbeats are recommended.
Benefits of Extended Distance Cluster
•This configuration implements a single Serviceguard cluster across two data centers, and uses either Multiple Device (MD) driver for data replication.
•You may choose any mix of Fibre
•This configuration may be the easiest to understand, as it is similar in many ways to a standard Serviceguard cluster.
•Application failover is minimized. All disks are available to all nodes, so that if a primary disk fails but the node stays up and the replica is available, there is no failover (that is, the application continues to run on the same node while accessing the replica).
•Data copies are peers, so there is no issue with reconfiguring a replica to function as a primary disk after failover.
•Writes are synchronous, so data remains current between the primary disk and its replica, unless the link or disk is down.
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