11:52 a.m.
Hi Daniel,
I was referring to multiple types of controllers. For now, I think it is enough to have
only one optional VirtIO-SCSI controller per VM, and (on the ppc64) one obligatory SPAPR
VSCSI controller. The main question is how to handle the addresses when the VirtIO-SCSI is
disabled and there is only the SPAPR VSCSI controller, and how to handle if the user
enables VirtIO-SCSI after the creation of the VM (I think the addresses for the existing
disks must remain stable, so the controller index must be 1 for the VirtIO-SCSI and 0 for
the SPAPR VSCSI in this case).
Do you have any tips on how to implement the disk/cdrom addressing in these cases?
Thanks,
Vitor
-----Original Message-----
From: Daniel Erez [mailto:derez@redhat.com]
Sent: terça-feira, 24 de setembro de 2013 09:31
To: Vitor de Lima
Cc: engine-devel(a)ovirt.org
Subject: Re: [Engine-devel] Issues with VirtIO-SCSI
----- Original Message -----
> From: "Vitor de Lima" <vitor.lima(a)eldorado.org.br>
> To: "Daniel Erez" <derez(a)redhat.com>
> Cc: engine-devel(a)ovirt.org
> Sent: Tuesday, September 24, 2013 12:34:17 AM
> Subject: RE: [Engine-devel] Issues with VirtIO-SCSI
>
> Hi Daniel,
>
> I asked this question because I have implemented a filter to show only
> compatible disk interfaces (in change #17964). The main purpose of
> this patch is to hide the IDE interface type when creating disks for
> PPC64 VMs (since IDE is not supported on this architecture). If it was
> decided that the VirtIO-SCSI interface type should be hidden from the
> user in case it was disabled, I would have to modify that patch a little bit.
For consistency, I'll filter the interface from the list when VirtIO-SCSI is
disabled.
So yeah, keep that in mind when modifying your patch.
>
> Another issue is that in change #18622 the support for a
> PPC64-specific controller, the SPAPR VSCSI controller, was introduced.
> But the code was created based on the assumption that the VirtIO-SCSI
> controller was always present, and this isn't the case anymore. And
> another patch that I will work on really soon will add support to
> create disks that are connected to this interface.
Can you filter the option out or add a warning when VirtIO-SCSI is disabled?
>
> So, I would like some feedback before changing these patches. Is a
> validation on the backend enough to block the user from using an inexistent
controller?
> Should the frontend be changed as well? What would be a good approach
> to handle multiple SCSI controllers in a VM (were the presence of one
> of them is optional)?
You should block it in the engine on canDo and filter the option / warn about it
in the UI.
Regarding multiple controllers, are you referring to multiple types of
controllers or just multiple VirtIO-SCSI devices?
>
> Thanks,
> Vitor
>
>
>
> >-----Original Message-----
> >From: Daniel Erez [mailto:derez@redhat.com]
> >Sent: segunda-feira, 23 de setembro de 2013 17:06
> >To: Vitor de Lima
> >Cc: engine-devel(a)ovirt.org
> >Subject: Re: [Engine-devel] Issues with VirtIO-SCSI
> >
> >Hi Vitor,
> >
> >The new VirtIO-SCSI enabled checkbox is an indication whether to
> >attach a VirtIO-SCSI controller when running the VM.
> >It should be enabled automatically on cluster >= 3.3.
> >
> >When disabled, I think it's preferable not to add a new controller
> >automatically when running the VM as it requires creating/attaching a
> >new VmDevice - which we refrain of on VmInfoBuilder flows (and since
> >it might be confusing to the user...).
> >
> >As an alternative, I've planned to add a warning in the dialog or
> >create a canDo message to prevent running the VM at all.
> >I'm not sure we should hide the option from disk interfaces list as
> >it's already being filtered using VirtIoScsiEnabled
> >ConfigurationValue (and using OsInfo soon...).
> >
> >Let me know what you think and thanks a lot for the input!
> >
> >Daniel
> >
> >----- Original Message -----
> >> From: "Vitor de Lima" <vitor.lima(a)eldorado.org.br>
> >> To: engine-devel(a)ovirt.org
> >> Sent: Monday, September 23, 2013 10:42:39 PM
> >> Subject: [Engine-devel] Issues with VirtIO-SCSI
> >>
> >> Hi everyone,
> >>
> >> I have found some issues with this patch:
> >>
> >> http://gerrit.ovirt.org/#/c/18638/
> >>
> >> It allows the user to disable the VirtIO-SCSI disk interface during
> >> the VM creation. The problem is that the user still can add, attach
> >> and hotplug disks with the VirtIO-SCSI interface type, but when the
> >> user does so, libvirt automatically creates a LSI Logic SCSI
> >> controller and connects the new disk to it.
> >>
> >> How can this problem be solved? Should the VirtIO-SCSI interface
> >> type be hidden from the user in case it wasn't enabled, or should
> >> the engine enable the VirtIO-SCSI controller, hotplug it, then
> >> hotplug the disk into it transparently?
> >>
> >> Thanks,
> >> Vitor de Lima
> >>
> >> _______________________________________________
> >> Engine-devel mailing list
> >> Engine-devel(a)ovirt.org
> >> http://lists.ovirt.org/mailman/listinfo/engine-devel
> >>
>