this question came up in the context of a potential migration that I might have to do, as consequence of the upgrade to TrueNAS 12.0. I’m using GELI encryption on my FreeNAS 11.3-U5 filer and I understand that this encryption technology is deprecated under TrueNAS 12.0 since the move to ZFS 2.0.
The only “safe” way to upgrade is apparently to delete the encrypted POOL and recreate it without encryption and then after version upgrade to TrueNAS 12.0 with ZFS 2.0 use the Dataset Encryption going forward (if desired).
Now, how can I copy my data back-and-forth to survive the destruction of the pool?
Fortunately I have a secondary filer, which alreday holds replicated snapshots from the primary filer. (Total data size ~ 10 TB) .
My plan is as follows:
1.) Perform additional backup of everything, including data and keys to diffrent media, i.e. USB drives, cloud etc
2.) Test backup
3.) Save configration of primary filer
4.) While all servers still run FreeNAS 11.3-U5 destroy and recreate the pool on the primary filer - this time without encryption
5.) Then replicate back my snapshots from the secondary filer (where they already reside)
6.) Make latest snapshot “read-write” - if necessary (see question below)
7.) Restore saved configuration
- Have I missed something?
- Will the save/restore operation on configuration data preserve the existing users/groups/shares and permissions?
- What is the “correct way” to make the re-replicated snapshot “read-writable” again on the primary filer? I understand they are mounted in read-only mode to prevent them from being changed accidentally. So in essence: how to I make those the “Master Copy” again after restoration? I assume the command would be "zfs set readonly=off POOLNAME - is that all?
Does anybody have experience with such an approach?