Comment 0 for bug 1180281

SUMMARY: I get “Unable to connect to libvirt” when using xl toolstack with Xen 4.2.1 in Ubuntu 13.10 (and also in Ubuntu 13.04).

BACKGROUND: I am testing a fully updated (as of May 15) installation of Ubuntu 13.10 that includes the following packages:

libvirt (1.0.5-0ubuntu1))
virt-manager (0.9.4-2ubuntu3)
xen-hypervisor-4.2-amd64 (4.2.1-0ubuntu3.1)

Upon setting TOOLSTACK=xm in /etc/default/xen (as well as making a few needed tweaks to /etc/xen/xend-config.sxp), libvirt and virt-manager worked great. Yippee!

I guess that I should be happy that the xm toolstack still works with Xen 4.2.1 and quit while I'm ahead, but...

According to libvirt's documentation:

"libxl: Starting with Xen 4.2, the legacy XenD/xm toolstack is deprecated in favor of libxl, also commonly called libxenlight. libvirt supports this new Xen toolstack via the libxl driver. If XenD is enabled, the legacy xen driver consisting of the above mentioned channels will be used. If XenD is disabled, the libxl driver will be used."

See http://libvirt.org/drvxen.html.

In view of the above, I attempted to use xl (instead of xm) by setting TOOLSTACK=xl in /etc/default/xen. And after doing so (both with and without, the above mentioned tweaks to /etc/xen/xend-config.sxp), I received the following error when attempting to start virt-manager:

Unable to connect to libvirt.

unable to connect to 'localhost:8000': Connection refused

Verify that:
 - A Xen host kernel was booted
 - The Xen service has been started

Libvirt URI is: xen:///

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/connection.py", line 1027, in _open_thread
    self.vmm = self._try_open()
  File "/usr/share/virt-manager/virtManager/connection.py", line 1009, in _try_open
    flags)
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 102, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: unable to connect to 'localhost:8000': Connection refused