Migrating from base to OpenZFS: GELI drives, send/receive, and sysctls/loader.conf

[Lorenzo Perone]

Hi All,

I have followed regularly the development of openzfs for FreeBSD and I
guess I'm ready and eager to give it a first try on a 12.2 updated
system by using the port.

Particularly watching the (now a little outdated, but still good) talk
by Alan Jude @ EuroBSDCon 2019 was very encouraging.

What I'm planning as a first run is:

On the same machine:

- Boot with openzfs_load instead of zfs_load
- Import the "base" created pool with openzfs
- Create a new pool with openzfs
- Send/Receive and/or rsync data from the old to the new one

A few questions arised for which I didn't find an answer yet in the
official documentation.

1) Will a pool on GELI drives import well with openzfs too? I'd assume
yes, why shouldn't it. Just asking to correct me if there are any
precautions I should be taking or surprises to expect.

2) Will the "old" settings be honored by openzfs, such as
vfs.zfs.arc_min, vfs.zfs.arc_max in /boot/loader.conf?

3) Is there an openzfs_enable as opposed to zfs_enable in rc.conf (to
import/mount pools at boot)? Or is zfs_enable just compatible?

4) As far as I know, it should be possible to send/receive data from an
unencrypted dataset to an encrypted one. Is this advisable from an "old
base" zfs dataset (not encrypted, on geli) to a new openzfs one
(encrypted at the dataset level), or should we resort to rsync?

5) What's the actual current status on extended attributes? Will they be
retained in a send/receive from FreeBSD-"old" to FreeBSD-OpenZFS? I have
a few shares on that machine where macs have "dropped" their EAs via
AFP/SMB, what should I expect?

Thanks a lot for any attention by people who know this right away,

Best Regards,

Lorenzo