I have upgraded this server to kernel 220.127.116.11. The next backup cycle resulted in a minor disaster: The backup process deadlocked at removing the first LVM2 snapshot and the snapshot source volumes were blocking write accesses. A cleanup shutdown was impossible and I had to hard-reset the machine.
After some searching I found out that you apparently need lvm2 2.02.01 or later and devmapper 1.02.02 or later to successfully remove snapshot volumes now. Unfortunately neither of these versions is available for sarge from Debian or backports.org yet, so I had to make my own backports.
As it turned out (see below), it is also necessary to use 18.104.22.168 or to apply the patch from this email to older 2.6.16 versions in order to reliably remove snapshots.
If you are brave enough, you can get the backported packages by adding
deb http://blog.blackdown.de/static/debian/lvm/ sarge main deb-src http://blog.blackdown.de/static/debian/lvm/ sarge main
The repository contains debs for devmapper, dlm, lvm2, and lvm-common. The
Release files is signed with my GPG key. If you have a recent
apt version, you can authenticate the packages after importing the key with
wget http://blog.blackdown.de/static/gpg.asc -O - | \ sudo apt-key add -
April 15th, 2006: In about 40 backup cycles I’ve seen three lockups with 22.214.171.124 now. Until snapshots get fixed in 2.6.16, I’d recommend to stay with 2.6.15. I’m using 126.96.36.199 again now.
April 24th, 2006: Added note about “dm snapshot: fix kcopyd destructor” patch from Alasdair G Kergon. With this patch snapshots work fine for me again.
May 2nd, 2006: Alasdair G Kergon’s patch has been included in 188.8.131.52.