Comment # 7 on bug 1043414 from Adrian Schr�ter

log attached.

Will apply your suggested workaround later today 

JFYI, this happens during prepare phase of the KVM builds. We always create a
fresh filesystem, install the absolut minimum system and copy in the rest of
the rpms and sources. Afterwards the filesystem gets unmounted (where it can
hang) and installation and build happens when the KVM session is running.

We don't mount afterwards due to security concerns, but export the result
directly from block device.

Thanks!