[libvirt-users] RHEL6 cgroup error after a few days of uptime

[Daniel P. Berrange]

On Thu, Dec 13, 2012 at 01:31:27PM -0700, Dax Kelson wrote:
> I have a RHEL6 that hosts many kvm virtual machines. It has been
> working fine for a couple years. I apply errata updates about once a
> week.
> 
> In the last couple weeks, I've ran into a bug where the virtual
> machines start failing to start with a cgroup error message. If I
> reboot the host (very disruptive) then things start working normaly
> for a few days.

Sounds like something has either unmounted your cgroups, or
deleted the directories that libvirt created. I wonder if the
cgconfig initscript is doing it perhaps, and getting triggered in
a %post from an RPM script. In any case, you ought not need to
reboot the host - restarting libvirtd will get it to re-create
its cgroups.

> Can I configure qemu/libvirt not to use cgroups at all as a temporary
> workaround? How would I do that?

Simply don't mount any on the host and libvirt won't use them.
On RHEL6, the 'cgconfig' initscript is what mounts them at boot.

Daniel
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