offline offsite backup via zfs

[ricotta]

Hello,

I couldn't find any answer that would satisfy me, so had to create this thread.

Before I can afford an offsite server, I'd like to implement a poor man's offsite backup by copying data to separate HDDs and dropping those to family members located far away (at least 100 km) whenever I visit them.

What I have is PBS in LXC running on ZFS. It's been like that for years, and I'd like to avoid changing that setup.

PBS in LXC does not really support removable datastores, as adding removable disks to LXC seems to be a PITA (if even possible).

So what I was thinking about is to reuse classing zfs datastore cloning, which would go as follows:

1. Shut down PBS LXC
2. Snapshot datastores
3. Start PBS LXC
4. For each datastore snapshot: zfs send pbs-pool/datastore@snapshot | zfs recv backup-pool/datastore
5. Remove the original snapshots

I understand that this solution should be self-sufficient, which I define as I could add the backed-up datastore to any PBS instance.

Disadvantages of this solution in comparison to removable datastores or PBS sync jobs would be:
- no control regarding backup depth
- possible garbage (because prune/gc jobs might not have run before snapshotting)
- more prone to human errors

Is all of that right? Is there anything to add?