Freenas (started around 8 or 9) to Truenas Core and now moving to Truenas Scale. I’m running Plex, Sonarr, Radarr, Transmission, and Squid. What should I be backing up for the move to Scale? I also have a couple of CIFS shares, do I need to do anything with those before the move? Looking through the documentation it is clear that the jails no longer work, does that mean they’re no longer accessible?
Take a look at Preparing to Migrate | TrueNAS Documentation Hub (and the rest of the migration guide) if you haven’t. The jails will not survive the migration, so you’ll need to save your configuration options, back up all app data, and then redeploy using the apps system in TrueNAS Community Edition (formerly SCALE). CIFS shares should continue to function as SMB shares after migration, though if you have any auxiliary parameters configured you should remove those before upgrading.
Since your running Plex you need to also consider if you are doing any Hardware transcoding. If you are, you will need to check if your card is supported in 25.10. If it is not, you might want to consider going to 25.4 instead to retain support for it. Otherwise you will need to upgrade your card or go through the procedure below to swap in the older Nvidia drivers to keep using your existing card.
The jails not surviving, is that they won’t operational or won’t be accessible, or won’t even be there? Know of any guidance for how to back up application settings?
What are “auxillary parameters” (I’m guessing that my having to ask means I don’t have any, but want to be sure.)
The ~arrs have their own backup functionality, in the System section of the app.