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

[Guan Qiang]

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:

<domain type='lxc' id='13071'>
   <name>instance-0000002b</name>
   <uuid>cf76c280-ac9c-44a6-94e3-237b46a7a68b</uuid>
   <memory unit='KiB'>2097152</memory>
   <currentMemory unit='KiB'>2097152</currentMemory>
   <vcpu placement='static'>1</vcpu>
   <os>
     <type arch='x86_64'>exe</type>
     <init>/sbin/init</init>
     <cmdline>console=tty0 console=ttyS0</cmdline>
   </os>
   <clock offset='utc'/>
   <on_poweroff>destroy</on_poweroff>
   <on_reboot>restart</on_reboot>
   <on_crash>destroy</on_crash>
   <devices>
     <emulator>/usr/lib/libvirt/libvirt_lxc</emulator>
     <filesystem type='mount' accessmode='passthrough'>
       <source 
dir='/opt/stack/data/nova/instances/cf76c280-ac9c-44a6-94e3-237b46a7a68b/rootfs'/>
       <target dir='/'/>
     </filesystem>
     <interface type='bridge'>
       <mac address='fa:16:3e:7a:1b:c8'/>
       <source bridge='br100'/>
       <target dev='veth0'/>
       <filterref filter='nova-instance-instance-0000002b-fa163e7a1bc8'/>
     </interface>
     <console type='pty' tty='/dev/pts/2'>
       <source path='/dev/pts/2'/>
       <target type='lxc' port='0'/>
       <alias name='console0'/>
     </console>
   </devices>
   <seclabel type='none'/>
</domain>

I still don't understand why I can't hotplug attach disk device for the 
lxc domain.
Expect more detailed answer, Thanks!