Are Lemmy.world servers located in Australia? Google says Europe so it seems like this is a non-issue.
Most social media have corporate entities in many of the countries they serve because they want sales people to sell that ad space and bank accounts to receive that ad revenue through, so usually the means of enforcing this would be to fine those entities/bank accounts. But I doubt lemmy.world would have much connection to Australia.
Or are there provisions in the law that would let them block the servers?
Contrary to a lot of posts that I have seen, I would say ZFS isn’t pointless with a single drive. Even if you can’t repair corruption with a single drive knowing something is corrupt in the first place is even more important (you have backups to restore it from right?).
And a ZFS still has a lot of features that are useful regardless. Like snapshots, compression, reflinks, send/receive, and COW means no concerns about data loss during a crash.
BTRFS can do all of this too and I believe it is better about low memory systems but since you have ZFS on your NAS you unlock a lot of possibilities keeping them the same.
I.e. say you keep your T110ii running with ZFS you can use tools like syncoid to periodically push snapshots from the Optiplex to your T110.
That way your Optiplex can be a workhorse, and your NAS can keep the backup+periodic snapshots of the important data.
I don’t have any experience with TrueNAS in particular but it looks like syncoid works with it. You might need to make sure that pool versions/flags are the same for sending/receive to work.
Alternatively keep that data on an NFS mount. The SSD in the Optiplex would just be for the base OS and wouldn’t have any data that can’t be thrown away. The disadvantage here being your Optiplex now relies on a lot more to keep running (networking + nas must be online all the time).
If you need HA for the VMs you likely need distributed storage for the VMs to run on. No point in building an HA VM solution if it just moves the single point of failure to your NAS.
Personally I like Harvester, but the minimum requirements are probably beyond what your hardware can handle.
Since you are already on TrueNAS Scale have you looked at using TrueNAS Scale on the Optiplex with replication tasks for backups?