[arch-general] Systemd with encrypted Btrfs

[Tom Gundersen]

On Tue, Jul 24, 2012 at 10:58 AM, Aurko Roy <roy.aurko at gmail.com> wrote:
> 1. I have an encrypted swap that randomly generates a new passphrase
> everytime I reboot, but systemd asks me for a  passphrase every time I
> boot. On pressing enter or entering any random characters it proceeds
> normally.  This is more of an annoyance than a real problem.

Note that systemd does not support Arch's traditional crypttab syntax,
so you might need to adjust your crypttab file. The format is
described in "man crypttab". I have a similar setup to what you
describe and my crypttab line is:

# cat /etc/crypttab
swap    /dev/sda2       /dev/urandom    swap

> 2. I have an encrypted btrfs partition which it unlocks normally, but
> while trying to mount says:
> "fsck: fsck.btrfs: not found
> fsck: Error 2 while executing fsck.btrfs for /dev/mapper/myvolume" and
> this stops the whole boot process. I have to disable that partition on
> fstab to get systemd to boot properly. Once the boot process is
> complete, I can see that the decryption has proceeded normally (from
> systemctl -a) and can remount it normally in a manual fashion. I
> initially thought that creating fsck.btrfs as a symlink to btrfsck
> might do the job, but that doesn't work either.

There is no fsck.btrfs binary yet, and btrfsck does not support the
expected interface. Until a proper fsck.btrfs exists you should mark
your partition as not wanting to be fsck'ed in fstab (i.e. set passno,
the last argument, to 0).

> Does anybody have any experience successfully mounting (encrypted or
> not) btrfs partitions using systemd?

I would have thought you'd get a similar failure also with
initscripts? Though in that case boot would not pause.

-t