About conditions for support of replicated NetBackup catalogs
A NetBackup environment set up for replication is supported in the same way as any other NetBackup server. If the replicated catalog volume fails and is unrecoverable within a reasonable amount of time, NetBackup support recommendations are the same as in the case of an unrecoverable disk failure of a non-replicated catalog. You should restore the catalog from the latest available catalog backup on the primary master server.
Note:
Data can be lost in any data replication solution. To protect the NetBackup catalog, you must not solely rely on the replication technology due to the risk of failure of the replication technology. Data on the primary NetBackup server can get corrupted due to replication to the secondary hot standby NetBackup server. Therefore, you must frequently back up the NetBackup server catalogs.
Warning:
Replication can adversely affect the application performance. Since additional time is required to commit changes to the NetBackup catalog, it may affect the overall backup times. Use replication at your own risk. Veritas shall have no liability for any replication failure based on your failure to properly install, configure, and monitor your replication solution.
The conditions of support for replication of NetBackup catalogs are as follows:
The replication technology that is employed must maintain a consistent and write-ordered copy of the data at all times.
The use of asynchronous replication technologies is allowed, if write-order fidelity can be maintained.
The use of scheduled replication technologies such as hourly snapshots is not supported.
The NetBackup master server must reside on the same virtual server that is controlled as a single entity.
The primary and the secondary master servers must be of similar type, specification, operating system, and use the same virtual host name.
The secondary master server must not have any other NetBackup function, neither in the same domain as the primary master server, nor in another domain. For example, you cannot use the secondary master server as a media server if it is not used as a master server. You also cannot use it as a master server for another NetBackup domain. Catalogs are replicated but cannot be merged.
Configure both the clustered and the non-clustered environments to use a virtual hostname and IP address for the NetBackup master server that is separate from the physical host names and IP addresses of the servers. Separate virtual hostname and IP address let you control the active master server node through DNS routing. It also prevents the primary and the secondary master servers from being active in the domain at the same time. For clustered environments this requirement is met automatically by the cluster configuration. For non-clustered environments the virtual hostname must be specified during installation.
Ensure that the primary master server and the secondary master server use the same version of NetBackup and dependent component. Verify that the operating system, NetBackup binaries, EEBs, and configurations files that are not included in the paths are specified for replication.
Replication between clustered and non-clustered master servers is not possible. Server pairs must be either clustered or non-clustered.
The NetBackup catalog mount point must be the same at both the primary and the secondary sites.
Only the catalog data is replicated between servers and must all be co-located on a single volume or volume set for replication. For clustered master servers the cluster common volume is replicated.
For non-clustered master servers, for details of the paths that must be linked to a volume set for replication,
Ensure that the virtual name or DNS alias does not resolve to both the primary and the secondary hosts at the same time.
Catalog replication does not remove the requirement for catalog backup. Regularly back up the NetBackup catalog from the primary master server to protect against accidental image expiration or other inconsistencies that are introduced in the catalog on the primary site and replicated to the secondary site.
If catalogs are replicated between NetBackup domains (rather than to a secondary server that can access the primary domain's media servers) only the backups that are written to the tape and the replicated BasicDisk storage can be restored in the disaster recovery domain.
Replication of the catalogs to a secondary master server lets you restore data during a short-term outage of the primary master server. In cross domain replication configurations, ensure that backups can be run after a failover. The catalogs should be able to be failed back to the primary server at a later date without data loss. Consider this support condition when you plan making backups at the DR site during a prolonged outage and then moving back to the primary site without losing information about the backups that are created at the DR site.
Verify if NetBackup comes up using the replicated copy on the secondary site. This usage is not a requirement for support.
Both the catalog and the backup images must be accessible at the secondary site.
Users need to address the procedures that are related to availability of valid copies of the backup images. Users should also define procedures for enabling the NetBackup server to restore from the images at the secondary site. This document does not address these procedures.
Users are responsible for installing, configuring, and monitoring their data replication solution. Users must ensure that the replication technology continuously maintains a consistent write-ordered copy of the NetBackup catalog volume.
Microsoft Distributed File System Replication (DFSR) technology is not supported as it does not guarantee write-ordered consistency of the files being replicated.
For more information, see https://www.veritas.com/support/en_US/article.100043283