About clustering considerations
The NetBackup master server nodes on both the sites must be configured as clustered master servers, although they can be single node clusters on each site.
The NetBackup master server can only run on one node of the cluster at any one time. In a replicated environment, the cluster members at both sites effectively form a single cluster. You can create a global cluster with two to four nodes, depending on the level of resilience required.
Single node cluster at both sites | This configuration requires two nodes - one node at each site. This configuration is the most efficient in terms of the servers involved. The disadvantage of this configuration is that even a local problem with the primary master server requires a site failover operation. |
Dual node on primary site and single node on secondary site | This configuration requires three nodes - two at the primary site and one at the secondary site. During normal operations, since there is single node at each site, site failover is not required to address issues with the primary master server. Instead a local failover can be used. However, there is no protection for the node on the secondary site. As a general best practice, this configuration is recommended. |
Dual node on both sites | This configuration requires four nodes, three of which are always idle. This configuration allows local failover capability at sites. With this configuration, if a local server problem is encountered, there is no need to failover. |