Encrypted LVM root FS does not boot any more

A newer Proxmox update obviously makes (some?) encrypted systems unbootable.

I have been running a fully encrypted Proxmox System (incl. root) for several weeks now without any problems (using a 3ware raid controller).

But today I tried to reboot and the reboot failed: Instead of showing the password prompt the system waits a little an then reports that it cannot find any lvm volumes. (When I use the Grub entry for the non-pve-kernel everything works fine. )

To find the reason for this problem I made a fresh install on the same machine but on another set of harddisks:

I installed Debian Squeeze 64 bit on a manually configured fully encrypted lvm (as I did successfully many times before) and rebooted.
After that I added the Proxmox Repository to sources.list and made an "aptitude update" and "upgrade".

Three packages were upgraded:
http://download.proxmox.com/debian/ squeeze/pve libdevmapper1.02.1 amd64 2:1.02.74-1pve2 [128 kB]
http://download.proxmox.com/debian/ squeeze/pve dmsetup amd64 2:1.02.74-1 pve2 [68,8 kB]
http://download.proxmox.com/debian/ squeeze/pve lvm2 amd64 2.02.95-1pve2 [575 kB]

After that I tried to reboot and had the same problem as before: No password prompt, just a message that no logical volumes were found.

Obviously one of these three packages causes the encrypted system not to boot any more.

What can I do now?

 

I was so lucky that I still had an entry in grub for the old standard debian kernel that was still working.

1) I booted up using the old still working standard debian kernel
2) I made an aptitude remove libdevmapper1.02.1
3) I answered "no" to the proposals how to resolve the conflicts that a removal of this package would cause until this solution was proposed:
Deaktualisieren der folgenden Pakete:
1) clvm [2.02.95-1pve2 (now, stable) -> 2.02.88-2pve2 (stable)]
2) dmsetup [2:1.02.74-1pve2 (now, stable) -> 2:1.02.67-2pve2 (stable)]
3) libdevmapper1.02.1 [2:1.02.74-1pve2 (now, stable) -> 2:1.02.67-2pve2 (stable)]
4) lvm2 [2.02.95-1pve2 (now, stable) -> 2.02.88-2pve2 (stable)]

4) I answered "yes" and spoke out several prayers.
5) I rebooted and --- The password prompt was back!!!

Now everything seems to be working again and I am happy.

But a big warning to all users that have a fully encrypted system: Do not use the latest update that is offered by Proxmox!!!