Okay, now another one of my potential approaches has been shot down, my question is about replication.
If I set up my old two-drive NAS with a mirror pool again and set up a RAIDZ2 pool on the new one with four hard drive bays and four new hard drives, how do I replicate the mirror pool to the RAIDZ2 pool, so that the four-drive NAS can take over the role of the two-drive NAS as seamlessly as possible?
You should probably keep the post together instead of new posts. A lot of questions and answers could be duplicated about your setup.
ZFS to ZFS will probably be ZFS Replication. Replication Tasks | TrueNAS Documentation Hub
Rsync may also be an option. Everyone would need to know the details on if this is just moving just data or if there are apps, etc involved. The more details you provide in a single thread, the easier it is to give advice on options.
