Re: [Engine-devel] Empty cdrom drive.

From: "Ayal Baron" <abaron(a)redhat.com&gt; To: "Yaniv Kaul" <ykaul(a)redhat.com&gt; Cc: engine-devel(a)ovirt.org Sent: Wednesday, February 15, 2012 11:23:54 AM Subject: Re: [Engine-devel] Empty cdrom drive. ----- 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 > > > > > > _______________________________________________ > > Engine-devel mailing list > > Engine-devel(a)ovirt.org > > http://lists.ovirt.org/mailman/listinfo/engine-devel > > _______________________________________________ > Engine-devel mailing list > Engine-devel(a)ovirt.org > http://lists.ovirt.org/mailman/listinfo/engine-devel > _______________________________________________ Engine-devel mailing list Engine-devel(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel