Re: driver type raw-xz supports discard=unmap?

[Daniel P . Berrangé]

On Mon, Jul 25, 2022 at 08:51:42AM -0400, Chris Murphy wrote:
> 
> 
> On Mon, Jul 25, 2022, at 5:13 AM, Daniel P. Berrangé wrote:
> > On Fri, Jul 22, 2022 at 04:03:52PM -0400, Chris Murphy wrote:
> >> Is this valid?
> >> 
> >> `<disk device="disk" type="file">
> >> <target dev="vda" bus="virtio"/>
> >> <source file="Fedora-Workstation-Rawhide-20220721.n.0.aarch64.raw-xz"/>
> >> <driver name="qemu" type="raw-xz" discard="unmap"/>`
> >> `/>
> >> </disk>`
> >> 
> >> I know type="raw" works fine, I'm wondering if there'd be any problem
> >> with type "raw-xz" combined with discards?
> >
> > This is libvirt configuration, so libvirt-users@redhat.com is the better
> > list in general. That said, what is this 'raw-xz' type you refer to ?
> >
> > AFAIK, that is not a disk driver type that exists in either libvirt or
> > QEMU releases.
> 
> Huh, interesting. I have no idea then. I just happened to notice it in the 
> (libvirt) XML config that's used by oz.
> https://kojipkgs.fedoraproject.org//packages/Fedora-Workstation/Rawhide/20220721.n.0/images/libvirt-raw-xz-aarch64.xml

I don't see 'raw-xz' mentioned anywhere in the Oz code at

  https://github.com/clalancette/oz

was it a fork that's being used ?

> I've got no idea what happens if an invalid type is specified in
> the config. The VM's are definitely running despite this. I'll ask
> oz devs.

This is pretty surprising if they're actually running as it should
cause a fatal error message

error: unsupported configuration: unknown driver format value 'raw-xz'


With regards,
Daniel
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