Incremental file replication

Replication and Disaster Recovery Administration Guide for Hitachi NAS Platform

Part Number

The server supports incremental data replication, performed under control of the replication process. Incremental replication means that, after the initial copy, only changes in the source volume or directory are actually replicated on the target. Snapshots ensure the consistency of the replication.

Note: If the snapshot that was copied by the last successful replication copy is deleted, an incremental copy cannot be performed, so the full data set is replicated.

Incremental data replication uses the same data management engine as NDMP to copy:

  • The contents of an entire file system,
  • A virtual volume, or
  • An individual directory tree to a replication target.

Upon configuration of a replication policy and schedule, the incremental data replication process takes place automatically at the specified interval. The replicated data can be left in place (and used as a standby data repository). In addition, the replicated file system or directory can be backed up through NDMP to a tape library system for long-term storage (which can also be automated).

Incremental data replication supports the following targets for replication:

  • A file system or directory within the same server.

    Tiered storage technology ensures that replications taking place within a server are performed efficiently, without tying up network resources.

  • A file system, virtual volume, or directory on another server.
  • A file system, virtual volume, or directory on another server model.

Although the replication process schedules and starts all replications, replicated data flows directly from source to target without passing through the replication process.