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

[hzguanqiang]

Hi Daniel,

I noticed that the patch "Add support for hotplug/unplug of disk devices in LXC" you wrote had been merged into libvirt of version 1.0.2.
But when I used this function, it report an error with details as following:

ubuntu at lxc:~$ vir attach-device instance-0000002c disk.xml --config          
error: Failed to attach device from disk.xml
error: Unable to create device /proc/18377/root/dev/sdb: Permission denied

ubuntu at lxc:~$ vir attach-device instance-0000002c disk.xml
error: Failed to attach device from disk.xml
error: Unable to create device /proc/18377/root/dev/sdb: Permission denied

ubuntu at lxc:~$ cat disk.xml
    <disk type='block' device='disk'>
      <driver type='raw' cache='none'/>
      <source dev='/dev/dm-0'/>
      <target dev='sdb' bus='scsi'/>
    </disk>

ubuntu at lxc:~$ ll /dev/dm-0
brw-rw---- 1 root disk 252, 0 Jul 15 03:39 /dev/dm-0

ubuntu at lxc:~$ dpkg -l|grep libvirt
ii  libvirt-bin                      1.0.2-0ubuntu11                            programs for the libvirt library
ii  libvirt0                         1.0.2-0ubuntu11                            library for interfacing with different virtualization systems
ii  python-libvirt                   1.0.2-0ubuntu11                            libvirt Python bindings
 				
And in this lxc vm, through dmesg the following information can be seen:
ubuntu at lxc2:~$ dmesg
[433287.227288] type=1400 audit(1373874475.861:55): apparmor="DENIED" operation="mknod" info="Failed name lookup" error=-13 parent=1 profile="/usr/sbin/libvirtd" name="dev/sdb" pid=1541 comm="libvirtd" requested_mask="c" denied_mask="c" fsuid=0 ouid=0

What's the real problem and How can I fix it.  I really appreciate your help.
Thanks!
--------------
Best regards!
GuanQiang
2013-07-15