Setting Up a Remote Replication Task

Start by configuring the replication sources. Sources are the datasets or zvols with snapshots to use for replication. Choosing a remote source requires selecting an SSH connection to that system. Expanding the directory browser shows the current datasets or zvols that are available for replication. You can select multiple sources or manually type the names into the field.

TrueNAS shows how many snapshots are available for replication. We recommend you manually snapshot the sources or create a periodic snapshot task before creating the replication task. However, when the sources are on the local system and don’t have any existing snapshots, TrueNAS can create a basic periodic snapshot task and snapshot the sources immediately before starting the replication. Enabling Recursive replicates all snapshots contained within the selected source dataset snapshots.

Local sources can also use a naming schema to identify any custom snapshots to include in the replication. Remote sources require entering a snapshot naming schema to identify the snapshots to replicate. A naming schema is a collection of strftime time and date strings and any identifiers that a user might have added to the snapshot name.

The destination is where replicated snapshots are stored. Choosing a remote destination requires an SSH connection to that system. Expanding the directory browser shows the current datasets that are available for replication. You can select a destination dataset or manually type a path in the field. You cannot use zvols as a remote replication destination. Adding a name to the end of the path creates a new dataset in that location.

To use encryption when replicating data click the Encryption box. After selecting the box these additional encryption options become available:

• Encryption Key Format allows the user to choose between a hex (base 16 numeral) or passphrase (alphanumeric) style encryption key.
  
• Store Encryption key in Sending TrueNAS database allows the user to either store the encryption key in the sending TrueNAS database (box checked) or choose a temporary location for the encryption key that decrypts replicated data (box unchecked)

Using encryption for SSH transfer security is always recommended.

In situations where two systems within an absolutely secure network are used for replication, disabling encryption speeds up the transfer. However, the data is completely unprotected from eavesdropping.

Choosing no encryption for the task is less secure but faster. This method uses common port settings but these can be overridden by switching to the advanced options screen or editing the task after creation.

TrueNAS suggests a name based off the selected sources and destination, but this can be overwritten with a custom name.

Adding a schedule automates the task to run according to your chosen times. You can choose between a number of preset schedules or create a custom schedule for when the replication runs. Choosing to run the replication once runs the replication immediately after saving the task, but you must manually trigger any additional replications.

Finally, define how long you want to keep snapshots on the destination system. We generally recommend defining snapshot lifetime to prevent cluttering the system with obsolete snapshots.

Start Replication* saves the new replication task. New tasks are enabled by default and activate according to their schedule or immediately when no schedule is chosen. The first time a replication task runs, it takes longer because the snapshots must be copied entirely fresh to the destination.

Later replications run faster since the task only replicates subsequent changes to snapshots. Clicking the task state opens the log for that task.