[linux-lvm] Missing error handling in lv_snapshot_remove

[Andreas Pflug]

Am 06.08.13 19:37, schrieb Bastian Blank:
> Hi
>
> I tried to tackle a particular bug that shows up in Debian for some time
> now. Some blamed the udev rules and I still can't completely rule them
> out. But this triggers a much worse bug in the error cleanup of the
> snapshot remove. I reproduced this with Debian/Linux 3.2.46/LVM 2.02.99
> without udevd running and Fedora 19/LVM 2.02.98-10.fc19.
>
> On snapshot removal, LVM first converts the device into a regular LV
> (lv_remove_snapshot) and in a second step removes this LV
> (lv_remove_single). Is there a reason for this two step removal? An
> error during removal leaves a non-snapshot LV behind.
Ah, this explains why sometimes my backup stops: I take a snapshot,
rsync the stuff and remove the snapshot with a daily cron job, but I
observed twice that a non-snapshot volume named like a backup snapshot
was lingering around, preventing the script to work. So this is no
exotic corner case, but happens in real life.

I observe this since I dist-upgraded to wheezy.

Regards,
Andreas