On 30/10/2013 20:39, Guido Günther wrote: > On Wed, Oct 30, 2013 at 05:41:08PM +0100, Lorenzo M. Catucci wrote: >> Hi all; >> after getting the same cgroup errors after a test-upgrade of libvirt, >> I stumbled upon the wishlist report from Daniel Baumann archived at >> >> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=601757 > > This looks a bit like what we're adding to libvirt-bin atm: > > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=725261 >> >> and tried the mountcgroupsubsys.sh script proposed by Marcus Osdoba as >> archived at >> >> http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=45;filename=mountcgroupsubsys.sh;att=1;bug=601757 >> >> At least on my system, this restored libvirt/qemu functionality >> without doing any harm to lxc guests. > > The problem here is different though, it's not the mounting per se > that's the problem - it's the newer libvirt that requires a different > cgroup layout. So if somebody wants to help fixing this (I haven't had > time to even reproduce it) one would need to check what we need to do in > the preinst/postinst to make the upgrade work automatically. If this > can't be done we need to abort the upgrade and ask the user to shutdown > all vms. > Cheers, > -- Guido >
In my (very limited) experience, the upgrade can work automatically if and only if the system was not using a comounted cgroup hierarchy; otherwise, a reboot is needed before trying to restart the VMs, and the VM shutdown before upgrade should be mandatory. To reproduce the problem, it's enough if you run a VM on a system whose fstab contains the entry: cgroup /sys/fs/cgroup cgroup defaults 0 0 in this case libvirt-bin will not start any VM after the upgrade UNTIL THE SYSTEM IS REBOOTED without such fstab line in effect, since "When a cgroup filesystem is unmounted, if there are any child cgroups created below the top-level cgroup, that hierarchy will remain active even though unmounted; if there are no child cgroups then the hierarchy will be deactivated." https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt Thank you very much, yours lorenzo m catucci -- To UNSUBSCRIBE, email to debian-bugs-rc-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
