[libvirt-users] Hotplug of disk devices in LXC failed with libvirt of version 1.0.2

[Gao feng]

On 07/16/2013 01:29 PM, Guan Qiang wrote:
> 于 2013/7/15 17:32, Gao feng 写道:
>> On 07/15/2013 05:18 PM, hzguanqiang wrote:
>>> Hi, Gao Feng
>>>
>>> I've tried what you said, but still exists the problem:
>>>
>>> ubuntu at lxc:~$ vir attach-disk instance-0000002c   /dev/dm-0 sdb
>>> error: Failed to attach disk
>>> error: Unable to create device /proc/10366/root/dev/sdb: Permission denied
>>>
>>> I think finding what it means by saying 'Unable to create device /proc/10366/root/dev/sdb: Permission denied' is the key.
>>> But anyway, thanks for your help!
>>>
>> Do you have <idmap> configured for your lxc domain?
>> I just posted a patchset to fix the problem that failed to create device when user namespace enabled.
>>
>> BTW, does it work well if you directly write the configuration to the xml of lxc domain?
>>
>> Thanks
> Hi, Gao feng,
> 
> I tried to write the configuration in the xml as you said, and it works.
> 
> And I didn't set <idmap> configure for my lxc domain.  The xml content of my lxc domain is just as following:
> 
...
> I still don't understand why I can't hotplug attach disk device for the lxc domain.
> Expect more detailed answer, Thanks!
> 

it's because apparmor deny libvirt to create device node under directory /proc/10366/root/dev/.

I don't know if this will help you, you can have a try.

change the apparmor profile of libvirtd. check the /etc/apparmor.d/usr.sbin.libvirtd,
and add /proc/ rw.

Thanks!