Logical Volumes not mounted automatically

["Christoph Pleger" <Christoph.Pleger@cs.tu-dortmund.de>]

Hello,

two days ago, I replaced an armel architecture device with an armhf
architecture device (both of them running Debian 8) and connected the same
external USB disk as before to the armhf device, because some of the
disk's logical volumes contain only architecture-independent data and
therefore can be used without changes. I added the appropriate entries in
the /etc/fstab of the armhf device.

But I now have the problem that - in contrast to before - the disk's
logical volumes are not recognized automatically at boot time. The LVM
scan does not print any discovered devices on screen. Because of the
problem, I am prompted to enter the root password, then a rescue shell
starts. When, in that shell, I enter the commands 'pvscan',
'vgscan','lvscan' und 'lvchange -a y", the latter for every logical
volume, all LVs are recognized and activated. Then, I can mount the
filesystems with 'mount -a' and press Ctrl+D, so that the boot process is
continued.

So, manual activation of the LVs works. Any suggestions why automatic
activation does not work? Have I done something wrong, that is, are
additional steps required to let LVs which have been created on a specific
computer be discovered automatically at boot time on another computer? Or
should this work as is and we have a bug here?

Regards
  Christoph