[libvirt] Mounting a raw DVD

[Gerry Reno]

Adam Mooz wrote:
> On 2009-11-10, at 12:48 AM, Gerry Reno wrote:
>
>> Adam Mooz wrote:
>>> On 2009-11-09, at 11:46 PM, Gerry Reno wrote:
>>>
>>>> Adam Mooz wrote:
>>>>> Hello List,
>>>>>
>>>>> I'm attempting to pass a DVD drive of a headless server into a 
>>>>> virtual machine.  So far I've managed to mount *something* into 
>>>>> the VM, but it's being registered as a blank DVD within the VM. 
>>>>> When I mount /dev/dvd into the bare-metal machine it registers 
>>>>> normally as the DVD.  How do I pass physical drives into a VM and 
>>>>> back out using libvirt?  Command used:
>>>>> #virsh attach-disk Montreal /dev/dvd hdc --mode readonly --driver 
>>>>> phy --type cdrom
>>>>> Connecting to uri: qemu:///system
>>>>> Disk attached successfully
>>>>>
>>>>> VM XML file:
>>>>>
>>>>> <domain type='kvm'>
>>>>> <name>Montreal</name>
>>>>> <uuid>0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</uuid>
>>>>> <memory>2097152</memory>
>>>>> <currentMemory>2097152</currentMemory>
>>>>> <vcpu>1</vcpu>
>>>>> <os>
>>>>>   <type arch='x86_64' machine='pc-0.11'>hvm</type>
>>>>>   <boot dev='hd'/>
>>>>> </os>
>>>>> <features>
>>>>>   <acpi/>
>>>>>   <apic/>
>>>>>   <pae/>
>>>>> </features>
>>>>> <clock offset='utc'/>
>>>>> <on_poweroff>destroy</on_poweroff>
>>>>> <on_reboot>restart</on_reboot>
>>>>> <on_crash>restart</on_crash>
>>>>> <devices>
>>>>>   <emulator>/usr/bin/kvm</emulator>
>>>>>   <disk type='file' device='cdrom'>
>>>>>     <target dev='hdc' bus='ide'/>
>>>>>     <readonly/>
>>>>>   </disk>
>>>>>   <disk type='file' device='disk'>
>>>>>     <source file='(Mangled Purposely)'/>
>>>>>     <target dev='vda' bus='virtio'/>
>>>>>   </disk>
>>>>>   <interface type='bridge'>
>>>>>     <mac address='(mangled purposly)/>       <source bridge='br0'/>
>>>>>     <model type='virtio'/>
>>>>>   </interface>
>>>>>   <serial type='pty'>
>>>>>     <target port='0'/>
>>>>>   </serial>
>>>>>   <console type='pty'>
>>>>>     <target port='0'/>
>>>>>   </console>
>>>>>   <input type='mouse' bus='ps2'/>
>>>>>   <graphics type='vnc' port='-1' autoport='yes' keymap='en-us'/>
>>>>>   <video>
>>>>>     <model type='cirrus' vram='9216' heads='1'/>
>>>>>   </video>
>>>>> </devices>
>>>>> </domain>
>>>>>
>>>>
>>>> I haven't done this for a while but I believe you have to issue a 
>>>> 'detach' command afterwards.
>>>>
>>>> -Gerry
>>>>
>>>> --
>>>> Libvir-list mailing list
>>>> Libvir-list at redhat.com <mailto:Libvir-list at redhat.com> 
>>>> <mailto:Libvir-list at redhat.com>
>>>> https://www.redhat.com/mailman/listinfo/libvir-list
>>>
>>> # virsh detach-disk Montreal hdc
>>> Connecting to uri: qemu:///system
>>> error: this function is not supported by the hypervisor: only SCSI 
>>> or virtio disk device can be detached dynamically
>>>
>>> ? Also, I'm not sure if you understood my question.  When I pass in 
>>> the DVD device into the VM it registers as a blank DVD.  if I pass 
>>> in a non-existant folder it blows up, so I know it's reading 
>>> something from the real DVD drive.  Mounting the real DVD drive in 
>>> the bare-metal machine shows the files on the drive, but I cannot 
>>> get them to appear in the VM.  How do I get the same files to show 
>>> up in the VM (i.e. mount the DVD drive into the VM)?
>>>
>>>
>> I didn't see /dev/dvd in your xml.  If you attach it and then dump 
>> the xml what does it look like?  And then have you tried booting the 
>> VM with an xml file with this device and can you read the files on 
>> the device this way?
>>
>> The other thing is that maybe your version of libvirt is too old.  I 
>> think 0.7.1 is current.
>>
>> -Gerry
>>
>>
>> --
>> Libvir-list mailing list
>> Libvir-list at redhat.com <mailto:Libvir-list at redhat.com>
>> https://www.redhat.com/mailman/listinfo/libvir-list
>
> Booting with the drive specified within the XML also gives a blank DVD 
> in the VM, no luck there. It turns out I'm running libvirt 7.0, was 
> there a large change between 7.0 and 7.1 in the way they handle 
> mounting block devices?  
>
> Here is some more output:
> After mounting at runtime, not at boot to the VM.
> virsh # dumpxml Montreal
> <domain type='kvm' id='3'>
>   <name>Montreal</name>
>   <uuid>0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</uuid>
>   <memory>2097152</memory>
>   <currentMemory>2097152</currentMemory>
>   <vcpu>4</vcpu>
>   <os>
>     <type arch='x86_64' machine='pc-0.11'>hvm</type>
>     <boot dev='hd'/>
>   </os>
>   <features>
>     <acpi/>
>     <apic/>
>     <pae/>
>   </features>
>   <clock offset='utc'/>
>   <on_poweroff>destroy</on_poweroff>
>   <on_reboot>restart</on_reboot>
>   <on_crash>restart</on_crash>
>   <devices>
>     <emulator>/usr/bin/kvm</emulator>
>     <disk type='block' device='cdrom'>
>       <source dev='/dev/dvd'/>
>       <target dev='hdc' bus='ide'/>
>       <readonly/>
>     </disk>
>     <disk type='file' device='disk'>
>       <source file='/mnt/vmdrive/Montreal-ubuntu-media/montreal.vmdk'/>
>       <target dev='vda' bus='virtio'/>
>     </disk>
>     <interface type='bridge'>
>       <mac address='54:52:00:63:bf:8d'/>
>       <source bridge='br0'/>
>       <target dev='vnet0'/>
>       <model type='virtio'/>
>     </interface>
>     <serial type='pty'>
>       <source path='/dev/pts/1'/>
>       <target port='0'/>
>     </serial>
>     <console type='pty' tty='/dev/pts/1'>
>       <source path='/dev/pts/1'/>
>       <target port='0'/>
>     </console>
>     <input type='mouse' bus='ps2'/>
>     <graphics type='vnc' port='5900' autoport='yes' keymap='en-us'/>
>     <video>
>       <model type='cirrus' vram='9216' heads='1'/>
>     </video>
>   </devices>
>   <seclabel type='dynamic' model='apparmor'>
>     <label>libvirt-0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</label>
>     <imagelabel>libvirt-0f79ba7f-27bf-16a0-5887-6cfa2b5569f1</imagelabel>
>   </seclabel>
> </domain>
>
> virsh # version
> Compiled against library: libvir 0.7.0
> Using library: libvir 0.7.0
> Using API: QEMU 0.7.0
> Running hypervisor: QEMU 0.11.0
>
The only other problem that I can think of is that there is some type of 
permissions problem going on.

-Gerry