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I'm running Ubuntu 12.04.2 32 bits.

The error doesn't show up if I start gksudo virt-manager.

  • libvirt-bin is installed.
  • I don't know how to check for the daemon.
  • I am a member of libvirtd.

Output of ps ax | grep libvirt:

9225 ? Sl 0:04 /usr/sbin/libvirtd -d
9302 ? S 0:00 /usr/sbin/dnsmasq -u libvirt-dnsmasq --strict-order --bind-interfaces --pid-file=/var/run/libvirt/network/ --conf-file= --except-interface lo --listen-address --dhcp-range, --dhcp-leasefile=/var/lib/libvirt/dnsmasq/default.leases --dhcp-lease-max=253 --dhcp-no-override`

Output of ls -l /var/run/libvirt/libvirt-sock:

srwxrwx--- 1 root libvirtd 0 Set 13 15:04 /var/run/libvirt/libvirt-sock

Output of getent group libvirtd:


Detailed error message

Impossível conectar a libvirt:

Falha ao conectar socket a '/var/run/libvirt/libvirt-sock': Permissão negada

Verify that:
 - The 'libvirt-bin' package is installed
 - The 'libvirtd' daemon has been started
 - You are member of the 'libvirtd' group

A URI Libvirt é: qemu:///system

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/", line 1185, in _open_thread
    self.vmm = self._try_open()
  File "/usr/share/virt-manager/virtManager/", line 1167, in _try_open
  File "/usr/lib/python2.7/dist-packages/", line 102, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: Falha ao conectar socket a '/var/run/libvirt/libvirt-sock': Permissão negada
share|improve this question
The error doesn't show up if I start gksudo virt-manager – That Brazilian Guy Sep 13 '13 at 18:52
What are the contents of your /etc/libvirt/libvirtd.conf file? – Bruno Pereira Sep 13 '13 at 19:41
up vote 17 down vote accepted

Sometimes stupidity is the cause.

Rebooting the host OS solved the issue.

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After installation KVM run this command then that error will not occur again

sudo virt-manager

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whoa!!! What is this, How did this work? – Kishor Pawar Feb 10 at 6:07
It worked because of sudo. read explanation in another answer… – Kishor Pawar Feb 10 at 6:28
Should be the acepted answer. – Magno C Mar 13 at 21:23

I'm managing both Qemu and Virtualbox on my Ubuntu 14.02 machine, and after installing Virtualbox libvirt-bin failed to autostart. So check if libvirt-bin is running:

ps faux | grep libvirt-bin

if you don't see it in ps output - start in manually, then run virt-manager:

sudo service libvirt-bin start

share|improve this answer

The problem is discussed on Launchpad and the cause of this problem can be solved by installing the xen-utils package (xen-utils-4.4 on Ubuntu 14.04). I previously was getting around this issue by virt-manager through sudo at the command line.

share|improve this answer
xen is similar to kvm, if you already have kvm installed do not install xen. It override my kvm installation and my vms stopped running. when I removed xen back vms started running. – Kishor Pawar Feb 10 at 7:07

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