[systemd-devel] Possible race condition with LVM activation during boot

[suscricions at gmail.com]

El Thu, 7 Feb 2019 11:18:40 +0100
Peter Rajnoha <prajnoha at redhat.com> escribió:

> On 2/6/19 6:38 PM, suscricions at gmail.com wrote:
> > Hi,
> > 
> > First of all apologies if this is not the correct channel to request
> > for help with this issue. I've tried asking in Arch Linux forums
> > without luck for the moment.
> > 
> > Long story short, from time to time I'm dropped to a rescue shell
> > during boot because of a logical volume that cannot be found, so the
> > respective .mount service fails making the local-fs.target stop
> > normal boot process.
> > 
> > local-fs.target: Job local-fs.target/start failed with result
> > 'dependency'.
> > 
> > Under normal circumstances I'd assume that a logical volume should
> > be activated first in order to be mounted, but a few times mounting
> > happens first so causing the error. I think this can be a race
> > condition or something similar because strikes randomly. Booting
> > again avoids the problem for the moment, which happened twice
> > during past days.
> > 
> > All the relevant parts from logs and information about my system
> > partition scheme is posted here:
> > https://bbs.archlinux.org/viewtopic.php?pid=1830442
> > 
> > Hope some of you can help me to find the root cause and again
> > apologies if this is not the place or the issue is too obvious.
> >   
> 
> If there's a mount unit, it's bound to certain device for which
> systemd waits to appear on the system. So yes, the device must be
> activated first before the mounting happens. If device doesn't appear
> within a timeout, you usually get dropped to a rescue shell.
> 
> Please, if you hit the problem again, try to collect LVM debug info by
> running the "lvmdump -u -l -s" command that creates a tarball with
> various LVM-related debug info we can analyze. It contains content of
> the journal for the current boot, the udev environment, LVM
> configuration, device stack listing and various other useful
> information for more thorough debugging.
> 
> I'm adding CC linux-lvm, let's move this discussion there. Thanks.
> 

There's been a reply in Arch Linux forums and at least I can apply some
contingency measures. If it happens again I will provide more info
following your advice.

Many thanks!

--
Miguel