Virt-manager does not connect to libvirt/Xen? Xen 4.1.5 installed from source on Fedora 17.

[ranjith krishnan]

Hello,

I posted this yesterday to the Xen-devel list, posting it additionally to
the fedoraproject list too.
My problem is Virt-manager is unable to connect to the hypervisor
(explained below). However, xm list, xm info work fine.

So I followed the guide
http://wiki.xen.org/wiki/Xen_4.2_Build_From_Source_On_RHEL_CentOS_Fedora
and built/installed Xen from source, using grub2-mkconfig to rebuild grub
and was able to reboot
Dom0 with Xen successfully.

Then I installed packages for virt-manager.
# yum install libvirt-daemon-xen python-virtinst
libvirt-daemon-config-network libvirt-daemon-driver-network virt-manager
virt-viewer
Everything got installed except for one package. Got an error message "No
package* libvirt-daemon-driver-network* available."

Now when I start virt-manager, it is unable to connect to Xen and fails
with the following error.
# 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/lib64/python2.7/site-packages/libvirt.py", line 102, in
openAuth
      if ret is None:raise libvirtError('virConnectOpenAuth() failed')
  libvirtError: unable to connect to 'localhost:8000': Connection refused

# xm list and # xm info work fine. This means xend is running right ?

Did some searching, found an old thread
http://old-list-archives.xenproject.org/xen-users/2010-06/msg00880.html
Added *(xend-unix-server yes)* to xen configuration file xend-config.sxp
and added *export VIRSH_DEFAULT_CONNECT_URI="xen:///"* to root's .bashrc.
Still no luck.

This might help, # rpm -qa | grep libvirt
libvirt-daemon-xen-0.9.11.9-1.fc17.x86_64
libvirt-daemon-0.9.11.9-1.fc17.x86_64
libvirt-0.9.11.9-1.fc17.x86_64
libvirt-python-0.9.11.9-1.fc17.x86_64
libvirt-daemon-config-network-0.9.11.9-1.fc17.x86_64
libvirt-daemon-config-nwfilter-0.9.11.9-1.fc17.x86_64
libvirt-client-0.9.11.9-1.fc17.x86_64

So in summary,
Built and installed from source Xen 4.1.5, on Fedora 17.
Can boot into Xen Dom0, xm works, xend running, But virt-manager unable to
connect to Xen!

Please help.
I have tried to give as much info as I could. Do let me know if you need
more info.

-- 
Ranjith krishnan

[Dario Faggioli]

On mar, 2013-06-18 at 18:05 -0500, ranjith krishnan wrote:
>  Hello, 
>   
Hi again Ranjith,

>  I posted this yesterday to the Xen-devel list, posting it
> additionally
>  to the fedoraproject list too.
>  My problem is Virt-manager is unable to connect to the hypervisor
>  (explained below). However, xm list, xm info work fine. 
>   
Yes, I saw your other e-mail too, but I'm afraid I can't help much as I
always have:
 - used xl only, when building Xen from sources, 
 - used Fedora Xen packages only, when using libvirt stuff

:-(

>  So I followed the
>  guide http://wiki.xen.org/wiki/Xen_4.2_Build_From_Source_On_RHEL_CentOS_Fedora
>  and built/installed Xen from source, using grub2-mkconfig to rebuild
>  grub and was able to reboot 
>  Dom0 with Xen successfully. 
>   
Ok.

>  Then I installed packages for virt-manager.
>  # yum install libvirt-daemon-xen python-virtinst
>  libvirt-daemon-config-network libvirt-daemon-driver-network
>  virt-manager virt-viewer
>  Everything got installed except for one package. Got an error message
>  "No package libvirt-daemon-driver-network available."
>   
On my Fedora 18, I get this:

$ yum search libvirt-daemon-driver-network
...
...
====================================================================================
libvirt-daemon-driver-network.x86_64 : Network driver plugin for the libvirtd daemon

$ rpm -qa | grep libvirt-daemon-driver-network
libvirt-daemon-driver-network-1.0.6-3.fc18.x86_64

Anyway, I do not think this could be the cause of your issue.

>  Now when I start virt-manager, it is unable to connect to Xen and
>  fails with the following error. 
>  # 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:///
>   
I see... Just shooting in the dark here, and forgive me if it's a stupid
question, but is libvirtd running?

>  # xm list and # xm info work fine. This means xend is running right
> ?
>   
Indeed. You can double check that with something like:

$ ps aux | grep xend

or:

# service xend status

Although, I'm not sure the latter will work, considering you're not
using any Fedora RPM/SRPM...

>  So in summary, 
>  Built and installed from source Xen 4.1.5, on Fedora 17. 
>  Can boot into Xen Dom0, xm works, xend running, But virt-manager
>  unable to connect to Xen! 
>   
As I said, I'm really short in ideas/experience, sorry. Something I
would probably try is:
 - uninstalling your built version of Xen
 - installing Fedora 17's Xen packages
 - try libvirt with them

That would at least tell us more about where --if not what-- the issue
could be.

Regards,
Dario

-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

[ranjith krishnan]

Thanks for replying Dario,


Yes, I saw your other e-mail too, but I'm afraid I can't help much as I
>  always have:
>   - used xl only, when building Xen from sources,
>   - used Fedora Xen packages only, when using libvirt stuff
>  
I just want to get couple of DomUs running, that is all. I'm not particular
about which tool I use.
Virt-manager seemed easier/quicker, hence I picked that.

I did some reading on configuring DomUs using xl/xm and cfg files.
http://www.fclose.com/b/linux/2544/setting-up-lvm-backed-xen-domu/
http://www.fclose.com/w/Setting_Up_Xen_DomU_on_Fedora:_Unmodified_Fedora_...

So basically I create the cfg file, and do "xm/xl create xmf16install -c"
This is one of my cfg files.

name="xmf16install"
memory=2048
vcpus=1
disk=['phy:/dev/xenvg/xmf16lvm,xvda,w']
vif = [ 'bridge=br0' ]
kernel = "/home/fedora16pxe/vmlinuz"
ramdisk = "/home/fedora16pxe/initrd.img"
onreboot = 'restart'
oncrash = 'restart'

The CentOS/Fedora installers are being launched, but I think I am running
into a problem when the installers ask for HTTP location from where to
pickup the images for install. I got different kinds of errors each time (I
tried multiple installations (F15,16, F17, CentOS5).

Some of the errors I got from the anaconda installers were
(F12, CentOS5)
'' loader received SIGSEGV!  Backtrace:

[0x80488c4]
[0xc18420]
[0x818c9e3]
[0x806305c]
[0x806cbcb]
[0x806cd06]
[0x806d1b7]
[0x806c5ee]
[0x80623ec]
[0x8062b29]
install exited abnormally [1/1]
sending termination signals...done
sending kill signals...done
disabling swap...
unmounting filesystems...
/proc done
/dev/pts done
/sys done
/tmp/ramfs done
you may safely reboot your system"

F(15)
"Unable to read package metadata. This may be due to a missing    │
      │ repodata directory.  Please ensure that your install tree has    │
      │ been correctly generated.                                        │
      │                                                                  │
      │ Cannot retrieve repository metadata (repomd.xml) for repository: │
      │ updates. Please verify its path and try again  "

I am guessing there is a problem when it tries to connect to the internet
to download packages.
I have also attached my domU cfg file for reference in the email.

Could someone point out where am I going wrong ?

I just want to get couple of DomUs working and this is proving tougher than
I thought. :(
Is there something wrong with my cfg files. Or is something else the issue
here ?

>  >
>  I see... Just shooting in the dark here, and forgive me if it's a stupid
>  question, but is libvirtd running?
>
>  Yes, it is. 
# service libvirtd status
libvirtd.service - Virtualization daemon
  Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled)
  Active: active (running) since Thu, 20 Jun 2013 09:50:10 -0500
Main PID: 1248 (libvirtd)
  CGroup: name=systemd:/system/libvirtd.service


>  >
>  As I said, I'm really short in ideas/experience, sorry. Something I
>  would probably try is:
>   - uninstalling your built version of Xen
>   - installing Fedora 17's Xen packages
>   - try libvirt with them
>  
This was what I tried initially. Regular F17, then yum install Xen, and
Virt-manager just worked out of the box for me, and I was able to create
DomUs.

Sorry, I just seem to be running into multiple issues with this! Kindly
help.
Any pointers would be greatly appreciated.

If all else fails, I am willing to start with a fresh install of F18 as
Dom0 and try to install Xen from source on that. Would this help ? I
remember you telling me F18 with Xen 4.2 working well with the Virt-tools.


-- 
Ranjith krishnan

[Dario Faggioli]

On gio, 2013-06-20 at 05:32 -0500, ranjith krishnan wrote:
>  Thanks for replying Dario,
>  
>  
>          Yes, I saw your other e-mail too, but I'm afraid I can't help
>          much as I
>          always have:
>           - used xl only, when building Xen from sources,
>           - used Fedora Xen packages only, when using libvirt stuff
>  
>  
>  I just want to get couple of DomUs running, that is all. I'm not
>  particular about which tool I use.
>  
Mmm... So you do not need any specific/unpackaged version of Xen, or you
don't need to modify Xen's code or apply any specific patch to it? If
no, why bothering with building from sources?

If you don't need anything particular, using what the distro provides is
almost always waaay easier than building from scratch, and that is
_especially_ true for Xen! :-O

>  Virt-manager seemed easier/quicker, hence I picked that.
>   
Sure it is, but you seem to be adding unnecessary complications to the
whole process, by trying building Xen yourself.

>  I did some reading on configuring DomUs using xl/xm and cfg files.
>  http://www.fclose.com/b/linux/2544/setting-up-lvm-backed-xen-domu/
>  
>
> http://www.fclose.com/w/Setting_Up_Xen_DomU_on_Fedora:_Unmodified_Fedora_...
>  
>  
>  
>  So basically I create the cfg file, and do "xm/xl create xmf16install
>  -c"
>  This is one of my cfg files.
>  
>  
>  name="xmf16install"
>  memory=2048
>  vcpus=1
>  disk=['phy:/dev/xenvg/xmf16lvm,xvda,w']
>  vif = [ 'bridge=br0' ]
>  kernel = "/home/fedora16pxe/vmlinuz"
>  ramdisk = "/home/fedora16pxe/initrd.img"
>  onreboot = 'restart'
>  oncrash = 'restart'
>   
I don't see anything bad here (although, I use different ways for
installing guests, so I can't be sure).

>  The CentOS/Fedora installers are being launched, but I think I am
>  running into a problem when the installers ask for HTTP location from
>  where to pickup the images for install. I got different kinds of
>  errors each time (I tried multiple installations (F15,16, F17,
>  CentOS5). 
>   
I see but, as you said, the Xen side of the thing appears to be working
(you see the installers!). There might be other issues, but I've no clue
about them I'm afraid.

>  I am guessing there is a problem when it tries to connect to the
>  internet to download packages. 
>  
Could be... Is the bridge working?

>  I just want to get couple of DomUs working and this is proving
> tougher
>  than I thought. :(
>  
Well, I'm not saying it's always piece of cake, but when you decide to
build your own Xen instead of using what the distro gives you, you
committed 'voluntary manslaughter' against simplicity yourself! :-P

>          As I said, I'm really short in ideas/experience, sorry.
>          Something I
>          would probably try is:
>           - uninstalling your built version of Xen
>           - installing Fedora 17's Xen packages
>           - try libvirt with them
>  
>  
>  This was what I tried initially. Regular F17, then yum install Xen,
>  and Virt-manager just worked out of the box for me, and I was able to
>  create DomUs. 
>    
No, I'm sorry, but now I feel like I'm loosing you. Are you saying that
you installed Xen and virt-* with yum and you add it all working fine?
Well, if yes, why you abandoned that path?

>  Sorry, I just seem to be running into multiple issues with this!
>  Kindly help. 
>  Any pointers would be greatly appreciated.
>   
There's no need to be sorry, although I'm not sure I can see what is
happening and provide useful directions. At least nothing different from
_try_official_packages_, especially if you said that they were working.

>  If all else fails, I am willing to start with a fresh install of F18
>  as Dom0 and try to install Xen from source on that. Would this help ?
>  I remember you telling me F18 with Xen 4.2 working well with the
>  Virt-tools. 
>   
Again, and sorry for repeating myself, if you do this, _do_ install an
F18 (actually, at this time, you may want to go for F19) and _do_
install both Xen, libvirt and the libvirt tools with *yum*. Don't build
anything if you don't need it. :-)

I said, and I confirm here, that on Fedora 18 (and the same applies to
F19 Beta, at least the few times I tired) I have virt-manager and
virt-install working well, either with xend running (i.e., using the old
toolstack and the xen libvirt driver) or without xend (i.e., using the
new toolstack and the libxl libvirt driver), at least for basic
create/start/pause/suspend/resume/reboot/shutdown workflow.

Regards,
Dario

-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

[ranjith krishnan]

Mmm... So you do not need any specific/unpackaged version of Xen, or you
>  don't need to modify Xen's code or apply any specific patch
> to it? If
>  no, why bothering with building from sources?
>
>  If you don't need anything particular, using what the distro provides is
>  almost always waaay easier than building from scratch, and that is
>  _especially_ true for Xen! :-O
>
>  I am a graduate student, and this is for my final project. 
My intention is to make
some code changes in Xen and try some things out,
once I get DomUs working.
That is why I am trying to install from source.

>  I am guessing there is a problem when it tries to connect to the
>  > internet to download packages.
>  >
>  Could be... Is the bridge working?
>  
brctl shows me this. Does this mean everything is OK with the bridge ?
# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.001ec936a1c5 no em1
vif3.0
virbr0 8000.525400f132d7 yes virbr0-nic


>  > This was what I tried initially. Regular F17, then yum install
> Xen,
>  > and Virt-manager just worked out of the box for me, and I was able to
>  > create DomUs.
>  >
>  No, I'm sorry, but now I feel like I'm loosing you. Are you saying that
>  you installed Xen and virt-* with yum and you add it all working fine?
>  Well, if yes, why you abandoned that path?
>  
Since I am new to Xen, I tried the official packages (yum install,
virt-manager) just to get some familiarity and confidence working with the
system. I thought once I have those working I can install from source and
make changes.

>  Again, and sorry for repeating myself, if you do this, _do_ install an
>  F18 (actually, at this time, you may want to go for F19) and _do_
>  install both Xen, libvirt and the libvirt tools with *yum*. Don't build
>  anything if you don't need it. :-)
>
>  I said, and I confirm here, that on Fedora 18 (and the same applies to
>  F19 Beta, at least the few times I tired) I have virt-manager and
>  virt-install working well, either with xend running (i.e., using the old
>  toolstack and the xen libvirt driver) or without xend (i.e., using the
>  new toolstack and the libxl libvirt driver), at least for basic
>  create/start/pause/suspend/resume/reboot/shutdown workflow.
>
>
>   Ok. I will try F18 next time. But I want to keep that as my last resort, 
if
nothing else works.

Right now, I thought I can download the iso file for fedora, save the image
on to the hard disk and then use it to build the DomU with xl. If that
doesnt work, I will look towards F18.




-- 
Ranjith krishnan