[dm-devel] [Question] multipathd.service start failed when /var/run isn't mount

[Benjamin Marzinski]

On Thu, Jul 22, 2021 at 10:51:22AM +0800, lixiaokeng wrote:
> When we enable multipathd.service with systemctl and reboot,
> multipathd doesn't start and log "failed to create pidfile".
> 
> The reason is following:
> 
> The RUN is /var/run in multipath-tools. When we start linux, we
> mount a disk to /var. So if multipathd.service start before mount,
> it will fail to activate.(If mount firstly, multipathd will start
> successfully)
> 
> The RUN is defined in Makefile.inc:
> 
> ifndef RUN
>         ifeq ($(shell test -L /var/run -o ! -d /var/run && echo 1),1)
>                 RUN=run
>         else
>                 RUN=var/run
>         endif
> endif
> 
> Can it always be defined as run?

I believe all modern distributions make /var/run a symlink to /run.
However, if that's the case, then I don't understand why you are running
into this issue at all, since multipath should be using /run. What
multipath packages are you using?

-Ben

> 
> Regards,
> Lixiaokeng