[ovirt-users] python floppy in RunOnce mode

Juan Hernandez jhernand at redhat.com
Thu Oct 23 18:59:33 UTC 2014

On 10/23/2014 09:40 AM, Giulio Casella wrote:
> Hi,
> I'm trying to boot a vm with non persistent floppy using python ovirt 
> sdk (the "RunOnce" way in administrator portal), but guest OS can't see 
> floppy drive. The ultimate goal is to deploy floppy with sysprep 
> unattend.xml file for windows 7 pools of vm.
> Here is a snippet of code I use:
> -------------------------------------------------
> myvm = api.vms.get(name="vmname")
> content="This is file content!"
> f=params.File(name="foobar.txt",content=content)
> fs=params.Files()
> fs.add_file(f)
> payload=params.Payload()
> payload.set_type("floppy")
> payload.set_files(fs)
> payloads=params.Payloads()
> payloads.add_payload(payload)
> thevm=params.VM()
> thevm.set_payloads(payloads)
> action=params.Action(vm=thevm)
> myvm.start(action=action)
> xml = ParseHelper.toXml(action)
> print xml
> -------------------------------------------------
> As you can see, for debugging purpose, I print my xml action, and I get:
> -------------------------------------------------
> <action>
>      <vm>
>          <payloads>
>              <payload type="floppy">
>                  <files>
>                      <file>
>                          <name>foobar.txt</name>
>                          <content>This is file content</content>
>                      </file>
>                  </files>
>              </payload>
>          </payloads>
>      </vm>
> </action>
> -------------------------------------------------
> in the admin portal I can see my vm in "RunOnce" state, but no floppy is 
> present...
> In fact in the vm process command line
> (ps -ef | grep qemu-kvm | grep vmname) I can't see -drive option 
> referring to floppy (I only see 2 "-drive" options, referring to vm 
> system disk and to a correctly mounted cdrom ISO)
> What I'm doing wrong?
> (The engine is RHEV-M version 3.4.1-0.31.el6ev)

The problem is that using non persistent payloads isn't currently
supported, so basically your "payloads" element is silently ignored. You
have currently two alternatives:

1. Use persistent payloads:

  vm = vms.get(name="myvm")

You may also want to remove the payloads once the machine is configured,
but this isn't strictly required, as Windows will not try to locate the
sysprep floppy in subsequent boots. The only minor inconvenient is that
the users of the VMs will see the floopy and its content attached.

2. Use the builtin sysprep files (they are in

  vm = vms.get(name="myvm")
  initialization = params.Initialization()

This has the advantage that the sysprep floppy will be attached to the
VM only the first time it is booted. In subsequent boots it won't be

In 3.5 you will also be able to use sysprep support with your custom file:

 vm = vms.get(name="myvm")
 initialization = params.Initialization(
   custom_script="The text of your sysprep file"

Note that currently (in 3.4 and in 3.5) there is an issue with the name
of the file generated by the built-in sysprep support: it will always be
named "sysprep.inf", regardless of the operating system assigned to the
VM. If you want to use recent versions of Windows it has to be named
"Unattend.xml", so you will need to change the Windows template before
sealing it, adding the following registry entry:

  HKEY-LOCAL-MACHINE -> SYSTEM -> Setup -> UnattendFile = sysprep.inf

There is a bug open to avoid this:


Note also that the builtin sysprep support will only trigger if the VM
has been assigned a Windows operating system.

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