[Engine-devel] Empty cdrom drive.

[Ayal Baron]

----- Original Message -----
> On 02/15/2012 09:44 AM, Igor Lvovsky wrote:
> >    Hi,
> > I want to discuss $subject on the email just to be sure that we all
> > on the
> > same page.
> >
> > So, today in 3.0 vdsm has two ways to create VM with cdrom :
> >   1. If RHEV-M ask to create VM with cdrom, vdsm just create it
> >   2. RHEV-M doesn't ask to create VM with cdrom, vdsm still creates
> >   VM with
> >      empty cdrom. Vdsm creates this device as 'hdc' (IDE device,
> >      index 2),
> >      because of libvirt restrictions.
> >      In this case RHEV-M will be able to "insert" cdrom on the fly
> >      with
> >      changeCD request.
> >
> > In the new style API we want to get rid from stupid scenario #2,
> > because
> > we want to be able to create VM without cdrom at all.
> > It means, that now we need to change a little our scenarios:
> >   1. If RHEV-M ask to create VM with cdrom, vdsm just create it
> >   2. RHEV-M doesn't want to create VM with cdrom, but it want to be
> >   able to
> >      "insert" cdrom on the fly after this. Here we have two
> >      options:
> >      a. RHEV-M should to pass empty cdrom device on VM creation and
> >      use
> >         regular changeCD after that
> >      b. RHEV-M can create VM without cdrom and add cdrom later
> >      through
> >         hotplugDisk command.
> >
> > Note: The new libvirt remove previous restriction on cdrom devices.
> > Now
> >        cdrom can be created as IDE or VIRTIO device in any index.
> >        It means we can easily hotplug it.
> 
> I didn't know a CDROM can be a virtio device, but in any way it
> requires
> driver (which may not exist on Windows).
> I didn't know an IDE CDROM can be hot-plugged (only USB-based?),

It can't be hotplugged.
usb based is not ide (the ide device is the usb port, the cdrom is a usb device afaik).

The point of this email is that since we want to support being able to start VMs *without* a cdrom then the default behaviour of attaching a cdrom device needs to be implemented in engine or we shall have a regression.
In the new API (for stable device addresses) vdsm doesn't automatically attach a cdrom.

> perhaps
> I'm wrong here.
> Y.
> 
> >
> >
> > Regards,
> >      Igor Lvovsky
> >
> >
> > _______________________________________________
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> > Engine-devel at ovirt.org
> > http://lists.ovirt.org/mailman/listinfo/engine-devel
> 
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