Replication of client node data

Node replication is the process of incrementally copying, or replicating, data that belongs to backup-archive client nodes. Data is replicated from one Tivoli® Storage Manager server to another Tivoli Storage Manager server.

The server from which client node data is replicated is called a source replication server. The server to which client node data is replicated is called a target replication server. A replication server can function as either a source server, a target server, or both.

Use replication processing to maintain the same level of files on the source and the target servers. When client node data is replicated, only the data that is not on the target server is copied. As part of replication processing, client node data that was deleted from the source server is also deleted from the target server. If Tivoli Storage Manager, Version 7.1.1 or later, is installed on the source and target servers, client node data is marked for deletion during replication processing but it is not deleted until expiration processing runs on the target server.

If Tivoli Storage Manager, V7.1.1 or later, is installed on the source and target servers, you can maintain different versions of files on the source and target servers or you can maintain files for more or less time on the target server than they are being maintained on the source server. To do this, you must configure the source and target servers to allow the target server manage replicated files by using the target server policies.

If a disaster occurs and the source server is temporarily unavailable, client nodes can recover their data from the target server. If the source server cannot be recovered, you can convert client nodes to store data on the target server. When there is an outage, the source server can automatically fail over to a target server for data recovery.

If Tivoli Storage Manager, V7.1.1 or later, is installed on the source and target servers, you can use replication processing to recover damaged files. You must replicate the node to the target server before the file damage occurs. Subsequent replication processes detect damaged files on the source server and replace them with undamaged files from the target server.

To ensure high server availability, you can use node replication with clustering. In a clustered environment, a client is less likely to fail over to another server. If you replicate data from several source servers to one target server, there is a high dependency on the target server. A clustered environment eases the dependency on the target server.

For information about implementing a replication configuration, see Setting up the default replication configuration.