Unable to connect Xend with virt-manager

Question

I have installed debian 6.0.1a. I have install all XEN stuff. including xen kernel, libvirtd, ... but when i want to connect xend, virt-manager shows me this:

Verify that:

• A Xen host kernel was booted

• The Xen service has been started details:

  Unable to open connection to hypervisor URI 'xen:///': unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Permission denied Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/connection.py", line 971, in _try_open None], flags) File "/usr/lib/python2.6/dist-packages/libvirt.py", line 111, in openAuth if ret is None:raise libvirtError('virConnectOpenAuth() failed') libvirtError: unable to connect to '/var/run/libvirt/libvirt-sock', libvirtd may need to be started: Permission denied here is uname output:

  Linux debian 2.6.32-5-xen-amd64 #1 SMP Tue Mar 8 00:01:30 UTC 2011 x86_64 GNU/Linux

and also xend and libvirtd is runnig:

root@debian:/home/mazimi# /etc/init.d/libvirt-bin status
Checking status of libvirt management daemon: libvirtd running.

root@debian:/home/mazimi# /etc/init.d/xend start
Starting Xen daemons: xenstored xenconsoled xend.

permissions for livbirt-sock:

root@debian:/home/mazimi# ls -alih /var/run/libvirt/
total 12K
671017 drwxr-xr-x  3 root root    4.0K Apr 15 13:54 .
654083 drwxr-xr-x 18 root root    4.0K Apr 15 13:54 ..
670901 srwxrwx---  1 root libvirt    0 Apr 15 13:54 libvirt-sock
670928 srwxrwxrwx  1 root libvirt    0 Apr 15 13:54 libvirt-sock-ro
670870 drwxr-xr-x  2 root root    4.0K Apr 15 02:34 qemu

and also we have group named libvirt in /etc/group

When running libvirtd with verbose mode it behaves kind of stange:

root@debian:/var/log/libvirt# /usr/sbin/libvirtd --verbose
17:26:55.841: warning : qemudStartup:1832 : Unable to create cgroup for driver: No such device or address
17:26:56.128: warning : lxcStartup:1900 : Unable to create cgroup for driver: No such device or address

and waits infinitely.

Answer 1

The problem is with the xen config I think. I had a similar issue with connecting.

To solve this on you need to edit /etc/xen/xend-config.sxp, and uncomment the following line:

(xend-unix-server yes)

and then restart xend

http://www.xen-support.com/?p=338

Answer 2

Try with a different URI. For example, mine works with qemu:// on a xen host

# cat /etc/redhat-release 
CentOS release 5.4 (Final)

# uname -a
Linux xen01.example.com 2.6.18-164.6.1.el5xen #1 SMP Tue Nov 3 16:48:13 EST 2009 x86_64 x86_64 x86_64 GNU/Linux

# virsh -c qemu:///system version
Compiled against library: libvir 0.6.3
Using library: libvir 0.6.3
Using API: QEMU 0.6.3
Running hypervisor: QEMU 0.9.0

Different host running kvm

# cat /etc/debian_version 
squeeze/sid

xen02:~# uname -a
Linux xen02.example.com 2.6.32-bpo.5-amd64 #1 SMP Fri Jun 11 08:42:31 UTC 2010 x86_64 GNU/Linux

xen02:~# virsh -c qemu:///system version
Compiled against library: libvir 0.8.1
Using library: libvir 0.8.1
Using API: QEMU 0.8.1
Running hypervisor: QEMU 0.12.5

You can do it over TLS too from a remote host. See this post

Answer 3

I just figured this one out. I administer CentOS servers and I have Ubuntu workstation. I wanted to use virt-manager over SSH to my Xen dom0 servers.

The basic premise is that you have to have the same user account on your client (virt-manager) and server (Xen dom0), which basically means you have to use 'root' account on your workstation to run virt-manager. Since I've setup SSH keys on both of my Xen servers this also means I have to add keys to my root account.

Instructions (for Ubuntu 10.04.3 workstation)

First, you login as root and copy the SSH keys you need for the server:

sudo -i
cp /home/user/.ssh/id_rsa_xenServer /root/.ssh/id_rsa_xenServer
chown root.root /root/.ssh/id_rsa_xenServer
chmod 600 /root/.ssh/id_rsa_xenServer

You have to fork the ssh-agent to the 'root' shell:

ssh-agent /bin/bash
ssh-add /root/.ssh/id_rsa_xenServer

Now you connect to the server to check the authentication with the server:

ssh root@xenServer

You have to open virt-manager in "privileged" mode for this to work. This can be done with 'Alt+F2' in GNOME where you enter 'gksu virt-manager'.

It's not necessary to add or edit anything on the server side.

After the virt-manager is up and running you need to add connections to your Xen server:

• File > Add connection (a new window pops up)
• select 'Hypervisor': Xen
• select 'Connection': Remote tunnel over SSH (available hosts show up below)
• you can select a host from the list or enter a specific hostname in the 'Hostname' field, if you server is not listed.