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

[Freddie Cash]

On Mon., Feb. 15, 2021, 9:37 a.m. Lorenzo Perone, <
lopez.on.the.lists at yellowspace.net> wrote:

> 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 Particularly watching the (now a little outdated, but still good) talk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,
>

If this is a boot pool, create a new boot environment and reboot into it
before making any changes. In the new BE, install the port, update
loader.conf and test things out. So long as you don't do a "zpool upgrade"
or enable any new features, then you can always change BE at the loader
menu to revert back to the working config.

Doing it that way saved me a lot of headaches when trying to use the
openzfs packages (which don't work on 12.2). Had to eventually install via
the ports tree.

A bunch of sysctls are the same, a bunch are named slightly differently,
and there's a whole bunch of new ones. Best bet is to comment then all out
and see if the autotune setup works for you. If not, then tweak the new
sysctls as you go.

It's just zfs_enable in rc.conf for both base and port ZFS.

You can "zfs send" between versions without issue.

Can't help with the GELI or xattrs questions as I don't use those.

Hope that helps,

Cheers,
Freddie

Typos due to smartphone keyboard.

>