Re: [linux-lvm] F7 will not boot after running backup w/snapshot

[Gerry Reno <greno@verizon.net>]

Charles Marcus wrote:
> On 5/1/2008 4:30 PM, Gerry Reno wrote:
>>>> At least in the case where the snapshot is read-only (LVM1 default, 
>>>> LVM2 by config?), if the snapshot is lost, invalid, not removed 
>>>> from VG prior to reboot, when LVM comes back up it should see this 
>>>> and immediately know that it can just vgreduce VG --removemissing 
>>>> for the old snapshot.  In the case of rw (no LVM1, LVM2 default), 
>>>> it should be a user choice and LVM should prompt the user at boot 
>>>> as to whether to remove this old snapshot so it can attempt to 
>>>> activate the VG.  Unless the user knows that there were non-backup 
>>>> related lvm mods written during the snapshot (eg: pvmove) then the 
>>>> user will just answer yes and the system should boot.  This is how 
>>>> LVM should operate in this scenario.
>
>>> If you want your system to do that, update your initrd/initscripts
>>> accordingly to run the appropriate lvm2 commands to do that!
>
>> I can certainly do that. But I think this applies in the general case 
>> and should be included as standard behavior in LVM. This is a much 
>> more robust means of dealing with this scenario that having LVM just 
>> refuse to mount the volume when the only issue is a bad snapshot.
>
> Question...
>
> In Gerry's scenario here, if the snapshot volume had NOT been on a ram 
> disk, would he have had the problem he had or not?
>
Charles,
  Without knowing the exact cause of the hang there is no way to know if 
the ramdisk was at issue.  I doubt it myself, I ran a whole series of 
backups last night using the ramdisk snapshot and everything went fine.

Gerry