[systemd-devel] hinting systemd about what to do to make a device appear

[martin f krafft]

Hi,

on one of my machines, /srv/backup is an encrypted filesystem
sitting on top of a DRBD volume. In /etc/crypttab, I thus have

  backup /dev/drbd/by-res/backup none noauto

and then I mount /dev/mapper/backup on /srv/backuppc.

systemd-cryptsetup-generated creates a unit for this which includes
the following lines:

  BindsTo=dev-drbd-by\x2dres-backup.device
  After=dev-drbd-by\x2dres-backup.device

But this device is unknown to systemd, which was informed by udev
only about sys-devices-virtual-block-drbd0.device.
/dev/drbd/by-res/backup is indeed a symlink to /dev/drbd0, but for
obvious reasons, I prefer using the named path, rather than the
arbitrary /dev/drbd0 name (which has in the past been /dev/drbd1
under certain circumstances).

So when I attempt to start the cryptsetup-volume:

  # systemctl start systemd-cryptsetup at backup.service

it times out waiting for dev-drbd-by\x2dres-backup.device, even
though the file in /dev (and DRBD) are ready to go.

Can I somehow give systemd the missing information, namely that in
order to provide this device, it needs to start drbd.service, or if
drbd.service is running, then the device can be assumed to exist?

Or what else would you suggest?

-- 
@martinkrafft | http://madduck.net/ | http://two.sentenc.es/
 
i stopped fighting my inner demons.. we're all on the same side now.
 
spamtraps: madduck.bogus at madduck.net
-------------- next part --------------
A non-text attachment was scrubbed...
Name: digital_signature_gpg.asc
Type: application/pgp-signature
Size: 1107 bytes
Desc: Digital signature (see http://martin-krafft.net/gpg/sig-policy/999bbcc4/current)
URL: <http://lists.freedesktop.org/archives/systemd-devel/attachments/20150910/fb683805/attachment.sig>