[fedora-virt] Is it possible to automatically swap CD during Fedora install in KVM?

[Li Ming]

On 03/11/2010 11:30 PM, James Laska wrote:
> On Thu, 2010-03-11 at 10:16 -0500, Cole Robinson wrote:
>> On 03/11/2010 08:47 AM, James Laska wrote:
>>> On Thu, 2010-03-11 at 16:24 +0800, Li Ming wrote:
>>>> Hi,
>>>>
>>>>       I want to use python to write an auto-test script to test fedora
>>>> install CD in KVM,my idea is: use virt-install to create a guest with
>>>> arguments --cdrom FedoraCD.iso, then the guest will boot with CD,with
>>>> the kickstart or something, the install will automatically
>>>> continue,after CD1 is finished, the anaconda will prompt to insert CD2,
>>>> I want all this automatic,meaning my script should detect the CD1
>>>> completed,and then swap to CD2, then the install continue. Is this
>>>> possible for libvirt? I have successfully written a script to do DVD
>>>> text install(totally imitate DVD install),you can see it at[1], I know
>>>> for CD,it's a challenge,you suggestion is very important to me.
>>>>
>>>> *[1]
>>>> http://git.fedorahosted.org/git/autoqa.git?p=autoqa.git;a=blob;f=tests/anaconda/dvd_install.py;h=5bcd3500cb724ac49753619e83911a034435cb3e;hb=5e78f629dc6b8315812585ba9d5b4801145fb5f7
>>>
>>> One approach, which might not reflect how users really install using CD
>>> media, would be to attach all CD media required to the guest during the
>>> install.  The installer will always check the attached optical devices
>>> for the disc it's looking for before prompting the user.  I've done this
>>> in the past, but it has the limitation that you can only attach a
>>> certain number of IDE CDROM devices to the guest at a time.
>>>
>>> With Xen, there was the xenstore-write command which could be used to
>>> change the ISO used for an attached block device.  I'm not sure if there
>>> is a similar command using just libvirt?
>>>
>>
>> This can be done with libvirt/virsh, it's just unintuitive. Say your VM has a
>> <disk>  block like:
>>
>>      <disk type='file' device='cdrom'>
>>        <driver name='qemu'/>
>>        <target dev='hdc' bus='ide'/>
>>        <source file='/some/path/to/media.iso'/>
>>        <readonly/>
>>      </disk>
>>
>> Copy that into its own file (say, 'test.xml') and change the<source>  line so
>> it looks like:
>>
>>      <disk type='file' device='cdrom'>
>>        <driver name='qemu'/>
>>        <target dev='hdc' bus='ide'/>
>>        <source file='/some/path/to/NEWMEDIA.iso'/>
>>        <readonly/>
>>      </disk>
>>
>> Then for the running VM, use:
>>
>> virsh attach-device VMNAME test.xml
>>
>> Full on removing the<source>  line will leave the CDROM empty, you still need
>> to use 'attach-device' though. We should really have a convenience command
>> 'eject' or something like that.
>
> Thanks, this process worked!
>
> -James
>

Great, it works here too. I also find this command also works :):
virsh # attach-disk vmname /path/to/new/CD2.iso hdc --type cdrom

Thanks
Liam