Bug#951549: systemd-fstab-generator: zfs entries in fstab should require zfs-import-scan or zfs-import-cache

[Fabian Grünbichler]

On February 18, 2020 11:06 am, Michael Biebl wrote:
> Am 18.02.2020 um 01:21 schrieb Peter B:
>> Package: systemd
>> Version: 244-3
>> Severity: normal
>> 
>> 
>> 
>> -- Package-specific info:
>> 
>> ZFS filesystems can be mounted through fstab, the zpool needs to be
>> imported before the mount. Currently systemd does not enforce
>> imports before mounts.
>> 
>> I demonstrably worked around this using this option in fstab:
>> 	'x-systemd.requires=zfs-import-scan.service'
>> 
>> I believe more generically all zfs filesystems in fstab should 'want' to
>> be 'after' the following services:
>> 	zfs-import-scan.service
>> 	zfs-import-cache.service
>> 
>> The three ways I know to have Debian import zpools:
>> - systemd: zfs-import-scan.service
>> - systemd: zfs-import-cache.service
>> - zfs kernel module parameter: zfs_autoimport_disable=0
> 
> zfs-import-scan.service and zfs-import-cache.service appear to be
> implementation details of zfs-linux.
> I don't think we should pull something like this into systemd,
> especially since no-one in the systemd team has ZFS knowledge (at least
> I don't have any idea if what you propose makes sense or not from a ZFS
> pov).
> 
> Finally, this would have to be added upstream first and not be
> maintained as downstream patch.
> For that you'd need to file a bug report at
> https://github.com/systemd/systemd/issues and convince upstream that
> what you propose is the right thing to do.

ZFS on Linux also ships an (opt-in) mount generator in recent versions, 
which should avoid the need to have any fstab entries at all for ZFS 
mount points when used together with zfs-zed.

https://manpages.debian.org/buster-backports/zfsutils-linux/zfs-mount-generator.8.en.html