After setting up a FreeNAS instance I was thrilled to learn that Ubuntu 20.04 LTS came with a ZFS installation option. I loved ZFS for my FreeNAS instance so loved the idea of using it on Ubuntu.
While there are some issues with it (e.g., if you run out of disk space you can quickly get stuck do to snapshotting issues...) it mostly worked great! But, I couldn't find a great way to back up the snapshots to Freenas. I tried sending the snapshots and kept getting errors about unsupported features (e.g., running a command like this and getting the below errors).
zfs send rpool/USERDATA/username_k7bgy9 | ssh email@example.com zfs recv -F nas/backup/backup-username
Error: Unsupported flag with filesystem or bookmark. cannot receive: failed to read from stream
cannot receive new filesystem stream: pool must be upgraded to receive this stream.
Well, no more!
I upgraded FreeNAS 11 to TrueNAS 12.0, and once I determined everything to be in working order I upgraded the pool. That did it!
All the features I had (by default) enabled in the Ubuntu 20.04 install were available on TrueNAS and I was able to send snapshots!
But note, you need to send snapshots, not datasets like this
zfs send rpool/USERDATA/username_k7bgy9@autozsys_1y5cd9 | ssh firstname.lastname@example.org zfs recv -F nas/backup/backup-username
I love when just waiting fixes the problem. But a shout out to TrueNAS, and the FreeBSD developers!