On Tue, Mar 29, 2011 at 02:55:28PM +0200, Jim Meyering wrote: > In case someone else encounters this... > > Today none of my VMs would start on F15: > > # virsh create rawhide.xml > error: Failed to create domain from rawhide.xml > error: Unable to create cgroup for rawhide: No such file or directory > > Luckily, I noticed that Rich Jones had the same problem > a week ago and he found that restarting libvirtd was enough > to solve the problem: > > # service libvirtd restart > > That did it for me, too. This is a bug in systemd. It periodically scans all mounted cgroups and deletes any directories which don't contain any attached processes. Needless to say this breaks libvirt, and possibly other apps, which don't expect 3rd parties to be deleting their directories. https://bugzilla.redhat.com/show_bug.cgi?id=678555