Error starting domain: Unable to create cgroup for debian6-test: No such file or directory
Traceback (most recent call last):
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 96, in cb_wrapper
callback(asyncjob, *args, **kwargs)
File "/usr/share/virt-manager/virtManager/asyncjob.py", line 117, in tmpcb
callback(*args, **kwargs)
File "/usr/share/virt-manager/virtManager/domain.py", line 1090, in startup
self._backend.create()
File "/usr/lib/python2.7/site-packages/libvirt.py", line 678, in create
if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self)
libvirtError: Unable to create cgroup for debian6-test: No such file or directory
cgroups are working:
# fgrep cgroup /proc/mounts
tmpfs /sys/fs/cgroup tmpfs rw,nosuid,nodev,noexec,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset,release_agent=/usr/lib/ulatencyd/ulatencyd_cleanup.lua 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpuacct,cpu,release_agent=/usr/lib/ulatencyd/ulatencyd_cleanup.lua 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,nosuid,nodev,noexec,relatime,memory,release_agent=/usr/lib/ulatencyd/ulatencyd_cleanup.lua 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0
cgroup /sys/fs/cgroup/net_cls cgroup rw,nosuid,nodev,noexec,relatime,net_cls 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio,release_agent=/usr/lib/ulatencyd/ulatencyd_cleanup.lua 0 0
And the libvirt node exists:
# ls -l /sys/fs/cgroup/libvirt/
total 0
drwxr-xr-x 2 root root 40 Oct 3 12:14 qemu
These VMs were previously defined and working on another Arch install on another hard drive, as recently as 2 weeks ago. Maybe libvirt is broken...?
Edit: I fixed this by reinstalling libvirt. I'm not sure what was wrong with my libvirt before, because it was persisting across reboots. Anyways, it's fixed now.
Edit 2: Actually, it seems that this still comes back from time to time, even when one VM is already running. To fix it I have to restart libvirtd (ie, systemctl restart libvirtd).