error: operation failed: failed to retrieve chardev info in qemu with 'indev'

[Rohan Nigam]

Hello Everyone,

I was not sure if I should report this as a bug before taking your opinions. But I have been using Ubuntu-10.10 Server to create KVM guests.

I used virt-install and vmbuilder tools to create these images. Using both I get the same error: operation failed: failed to retrieve chardev info in qemu with 'info char dev'

Here are some more details:
Machine: Ubuntu server -10.10 ubuntu 2.6.35-22-server
Libvirt and virsh versions:
root@ubuntu:/# virsh version
Compiled against library: libvir 0.8.3
Using library: libvir 0.8.3
Using API: QEMU 0.8.3
Running hypervisor: QEMU 0.12.5


virsh # list --all
Id Name State
----------------------------------
- mav-vm1 shut off
- mav-vm2 shut off

virsh # start mav-vm2
error: Failed to start domain mav-vm2
error: operation failed: failed to retrieve chardev info in qemu with 'info char dev'


At the beginning I was thinking the problem might be with vmbuilder or virt-install. Here are the commands I used:


vmbuilder kvm ubuntu --suite maverick --flavour virtual --arch amd64 -o --libvirt qemu:///system --ip 192.168.2.212 --hostname 'mav-vm2' --cpus 2 --mem '2048' --rootsize '8192' --swapsize '1024' --mask 255.255.255.0 --bcast 192.168.2.255 --gw 192.168.2.1 --dns 192.168.2.30 --bridge br0 --user rnigam --pass default --addpkg wget --addpkg cron --addpkg vim --addpkg ntp --addpkg ntpdate --addpkg ssh --addpkg build-essential --addpkg linux-headers-virtual --addpkg acpid

Using the ISO:
virt-install --connect qemu:///system -n mav-vm1 -r 2048 --vcpus=4 -f /root/vmimages/kvm1.qcow2 -s 12 --cpuset=4,5,6,7 -c /root/vmimages/ubuntu-10.10-server-amd64.iso --os-type linux --network bridge=br0 --accelerate --virt-type kvm --hvm


There was a suggestion from the #virt on OFTC and #ubuntu-server that this problem might be because of the older version of libvirtd running. (0.8.3) compared to the latest available libvirtd 0.8.8.

At this moment, I am unable to use KVM and libvirt on Maverick to create any guests at all. All comments and suggestions are welcome.

Thanks.

Rohan

[Rohan Nigam]

Ok I figured out what the problem was. Apparently this is Maverick related bug. I have checked and confirmed it with couple of guys on #ubuntu-server who were running Lucid. All the options in /etc/libvirt/qemu.conf are commented out by default.

I had to uncomment these two out:

# The user ID for QEMU processes run by the system instance
user = "root"

# The group ID for QEMU processes run by the system instance
group = "root"


This needs to be filed as a bug(if it can be called so)


- Rohan

[bl8n8r]

> I had to uncomment these two out:

I am getting this error from virt-manager (since recent update) when trying to start guests. Opteron 12 core system. Un-commenting those entries does not work for me.

[JonathanRRogers]

> I had to uncomment these two out:

I am getting this error from virt-manager (since recent update) when trying to start guests. Opteron 12 core system. Un-commenting those entries does not work for me.

Did you restart libvirtd? I used this command "sudo restart libvirt-bin".

[kkaland]

This is still relevant in Ubuntu 12.04 LTS, at least when running

virt-install

as root.