[virt-tools-list] permission denied for non-root virsh create

[Shantanu Pavgi]

Hi,

I am getting some 'permission denied' issues with libvirt/qemu while trying to create new VMs as a non-root user. The username trying to create these new VMs is part of the 'kvm' unix group and the 'kvm' group has rw permissions in the libvirtd.conf as:
{{{
unix_sock_group = "kvm"
unix_sock_rw_perms = "0770"
}}}

Following is the error I received:
{{{
$ virsh create /tmp/clearos2.xml
23:34:29.227: error : internal error Failed to add tap interface 'vnet%d' to bridge 'br0' : Permission denied
libvir: QEMU error : internal error Failed to add tap interface 'vnet%d' to bridge 'br0' : Permission denied
error: Failed to create domain from /tmp/clearos2.xml
error: internal error Failed to add tap interface 'vnet%d' to bridge 'br0' : Permission denied
}}}

I don't see any related logs in the libvirtd.log even at debug level.  Also, I have used OpenNebula cloud computing toolkit (http://opennebula.org/) with this KVM-libvirt install and it is able to create new VMs without root access. The OpenNebula uses libvirt API to interact with hypervisor so I am guessing libvirt configuration is fine. The OpenNebula user is part of the 'kvm' unix group as well and it does not have any other special privileges.

Is this error coming from qemu or virt-tools/virsh?  Any pointers on how to debug this will be really helpful.

System Info: CentOS 5.5 64-bit, KVM/kvm-qemu 83-164.el5, libvirt 0.6.3-33.el5_5.3.

Thanks,
Shantanu.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/virt-tools-list/attachments/20110419/86f1409f/attachment.htm>