Bug#756560: lvm2: cache_dir /run/lvm doesn't exist, ENOENT /run/lvm/.cache

[Zdenek Kabelac]

On Wed, 30 Jul 2014 15:54:32 -0600 Jacob Anawalt <jlanawalt at gmail.com> wrote:
> Package: lvm2
> Version: 2.02.95-8
> Severity: normal
>
> Dear Maintainer,
>
> I have installed fresh Debian 7 systems to do some testing with and found
> that the default configured cache_dir of "/run/lvm" does not exist under /run.
>
> When I strace vgscan, it gives the ENOENT error because it cannot open
> /run/lvm/.cache.
>
> The system us using tmpfs for /run as per the Debian defaults.
>
> I don't know what is suppose to create the lvm directory under /run
> on reboot, but it seems that something, perhaps /etc/init.d/lvm2,
> should to enable caching.
>

Upstream (original)  lvm2  stores .cache within  /etc/lvm dir which
is persistent across reboots.

Debian for unknown reason relocated this 'persistent' place to /run
which is cleared on every reboot - so losing the original purpose.

On the other hand on any modern distro which is using 'udev' scan,
this .cache file is actually not used - since the list of devices
is obtained from udev - so no big harm as the cache file is not even created...

Regards

Zdenek