How should we backup our 1TB < repositories’ data?

When dealing with very large repositories filestores and large databases Artifactory's built-in backup service could take significant time to complete running backup jobs.

For better control and performance, we suggest to use a third party IT backup solution with snapshot capabilities, which you should use to your $ARTIFACTORY_HOME location on your filesystem.

Databases wise - taking periodic snapshots of your external database (would probably need another tool for this) will complete the coverage or cases such as when data restoration from specific time is needed, or when version rollback is needed or recovery from any disaster events.

When restoring: you will be need and be able to restore a desired point in time by applying your HDD/filestore  together with your database snapshots to gain back your important Artifactory data. When doing this, aim to restore the closest timely made database and snapshot so that your backed-up information will be kept in sync.

In conclusion, a combination of both of the ideas presented above: keeping snapshots of your $ARTIFACTOY_HOME/$CLUSTER_HOME location and your database will get you back up to speed in the shortest time, and you could do that on top of keeping a separate backup of your Artifactory server(s) which should serve as another redundant backup point.