“Unable to connect to libvirt” when using virt-manager with the xl toolstack and Xen 4.2.1

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Please could you check /var/log/libvirt/ and post anything relevant?

Did you get the documentation with the XenD/xm deprecation warning from somewhere tied to this version of libvirt, or from the website in general? Are you able to check that the documentation you found applies to the version of libvirt that you're using, please?

It's probably also worth checking whether this bug affects upstream libvirt or just the Ubuntu packaging.

Once done, please change the bug status back to New. Thanks!

Hi Robie,

I posted the output from var/log/libvirt/libvirtd.log in the bug report.

I'll respond to your questions/comments here:

"Did you get the documentation with the XenD/xm deprecation warning from somewhere tied to this version of libvirt, or from the website in general?"

It is well known that XenD/xm has been deprecated in Xen 4.2. But since XenD/xm is still working and in widely used by many, Xen isn't exactly "warning" anyone about the deprecation. But they are gently encouraging users to make the move as soon as practical.

"Are you able to check that the documentation you found applies to the version of libvirt that you're using, please?" and "It's probably also worth checking whether this bug affects upstream libvirt or just the Ubuntu packaging."

I posted questions relate to this bug on the "<email address hidden>" and "<email address hidden>" lists. Based on the replies that I received, I'm under the impression that libvirt 1.0.5 (which I'm using) has been made to work with the xl toolstack in a few rpm based distros, including Fedora and openSUSE. However, I can't say for certain whether it is working straight from upstream or whether those distros include their own patched versions.

I realize that this bug report is still somewhat incomplete. But I want to leave it open with the hope that others will post additional information here. Hopefully, if enough post here, we'll be able to figure out what's going wrong.

Thanks!
GizmoChicken

Oh, I'll just add that, although this issue has not, to my knowledge, been reported as bug here on lauchpad, the issue has been mentioned by others in various forums, including the following: http://forums.linuxmint.com/viewtopic.php?f=42&t=112013&p=720628#p721199

Thanks. Given that others have the same issue, I think it's reasonable to mark this bug "Confirmed" and leave it open. Since this relates to a non-default configuration, I think "Medium" is the highest appropriate Importance level.

Thanks much. And medium sounds about right. I'll just add that the problem might actually be with libxl, which libvirt relies on to communicate with xl, rather that with libvirt itself. But I'll have that determination to someone with far more knowledge than me.

This also affects 13.04, and it isn't limited to virt-manager.

$ virsh -V && virsh -c xen:/// version
Virsh command line tool of libvirt 1.0.2
See website at http://libvirt.org/

Compiled with support for:
 Hypervisors: QEMU/KVM LXC UML Xen OpenVZ VMWare VirtualBox Test
 Networking: Remote Network Bridging Interface netcf Nwfilter VirtualPort
 Storage: Dir Disk Filesystem SCSI Multipath iSCSI LVM RBD Sheepdog
 Miscellaneous: Daemon Nodedev AppArmor Secrets Debug Readline Modular
error: failed to connect to the hypervisor
error: unable to connect to 'localhost:8000': Connection refused

This could be related to Debian bug #706059. It seems that the Xen driver isn't being loaded.

$ LIBVIRT_DEBUG=1 virsh -c xen:/// list 2>&1 | grep driver=
2013-05-31 14:57:29.879+0000: 3386: debug : virRegisterDriver:756 : driver=0x7f8deb633f00 name=Test
2013-05-31 14:57:29.879+0000: 3386: debug : virRegisterDriver:756 : driver=0x7f8deb635540 name=OPENVZ
2013-05-31 14:57:29.879+0000: 3386: debug : virRegisterDriver:756 : driver=0x7f8deb635b00 name=VMWARE
2013-05-31 14:57:29.880+0000: 3386: debug : virRegisterDriver:756 : driver=0x7f8deb6360c0 name=VBOX
2013-05-31 14:57:29.880+0000: 3386: debug : virRegisterDriver:756 : driver=0x7f8deb6348e0 name=remote

The problem appears to be missing libxenlight.so and include files in libxen-dev. During the libvirt configure run it looks for libxenlight.so but fails to find it since it is not in libxen-dev (It is in xen-utils-4.2).

I'm currently testing a build of the xen source package with xenlight added to libxen-dev.

There seem to be several incompatible issues introduced by the Debian packaging style:

1. Debian packages libxenlight.so into "xen-utils-4.2" along with the binary executables (/usr/lib/xen-4.2/bin/xl, etc.) - other distros package it in the libxen[-4.2] package
2. libvirt's configure script expects to find libxenlight.so in the standard library locations /usr/lib, /usr/lib/x86*-linux-gnu/
3. Debian installs libxenlight.so to /usr/lib/xen-4.2/lib/
4. Debian/Ubuntu libvirt does not depend on "xen-utils" (the virtual package provided by xen-utils-4.2).
5. Debian/Ubuntu libvirt configure script checks for but does not find libxenlight.so and therefore doesn't include support

I tried adding "xen-utils" as a build-depends to libvirt but that doesn't solve the issue due to [3].

I also tried adding libxenlight.so, libxenlight.a and libxl.h to the libxen-dev package but that fails to build due to other complex library dependencies which I decided not to pursue.

This problem still affects Ubuntu 14.04 (devel branch).

Has this been tested in 14.04 with libvirt 1.2.1? There was a bug when merging libvirt 1.2.0 which should be resolved now.

YAY! Working in Ubuntu 14.04 beta1! It comes with libvirt 1.2.1 as you said Stefan...

Seems to be okay now, virt-manager can at least, connect at my, PVM-only, Xen host (with XL stack) using "xen+ssh://administrative@xen-dom0/".

I'll keep testing it this weekend, first problem seems to be fixed by now.

NOTE: Next problem is now:

---
Unable to complete install: 'internal error: libxenlight failed to create new domain 'trusty-1''

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/create.py", line 1983, in do_install
    guest.start_install(False, meter=meter)
  File "/usr/lib/python2.7/dist-packages/virtinst/Guest.py", line 1246, in start_install
    noboot)
  File "/usr/lib/python2.7/dist-packages/virtinst/Guest.py", line 1314, in _create_guest
    dom = self.conn.createLinux(start_xml or final_xml, 0)
  File "/usr/lib/python2.7/dist-packages/libvirt.py", line 3199, in createLinux
    if ret is None:raise libvirtError('virDomainCreateLinux() failed', conn=self)
libvirtError: internal error: libxenlight failed to create new domain 'trusty-1'
---

But, of topic... I'll keep trying / researching...

Tks!

Closing this bug now as the connect issue should be resolved. Several other issues with libvirt have been resolved but I still need to get the latest package into the archive. Preview is in my ppa (ppa:smb/xen).

I have tried with ubuntu 14.04 and libvirt 1.2.2 and getting the same error what sir/madam Thiago Martins (martinx) reported.

any body has idea to solve this error "internal error:libxenlight failed to create new domain"

this error may be because of few packages not included in libvirt for libxenlight.

The logs (/var/log/libvirt/libxl) on the host may contain more info. It should work for HVM. If you try to start a PVM you may hit bug #1326003. If your issue is a different one, please open a new bug report.