About multi-site single domain replication
Multi-site single domain is used where clients and media servers at both sites are under control of a common primary server. Since both servers are part of the same domain, they see the same media servers and clients, and the NetBackup catalog is completely valid on the alternate primary server.
In the multi-site single domain model, NetBackup catalogs are replicated between the sites. In the event of a problem at the main site, the primary server is failed over to a standby node on the alternate site. Backups are created on both sites (either by in-line copy or duplication depending on the configuration). Thus, the loss of a single site does not represent a true disaster, but loss of a number of application servers. Because the backup domain spans both sites, the loss of a single site results in reduction of the backup and restore capability, rather than destroying the backup environment. The multi-site single domain model uses a combination of primary server clustering and storage replication. This combination allows the primary server to be relocated easily and quickly to the alternate location.
The multi-site single domain model can be configured in following ways:
Multi-site single domain with stretched SAN
Multi-site single domain with optimized duplication
See About multi-site single domain with optimized duplication.