Re: [Qemu-devel] [PATCH] qcow3 - arbitrary metadata

[Anthony Liguori]

Jamie Lokier wrote:
> Anthony Liguori wrote:
>   
> > Can you provide more information about what the metadata is used for and 
> > why it's so important for the metadata to be in the image verses in a 
> > separate file?
> >     
>
> Yeah, I have the opposite problem - too much in the same file :-)
>
> I want to be able to savevm, but some of my VMs don't have any qcow2
> images (because I don't trust them for mission-critical VMs since
> recent discussion,

How do you snapshot the disk images?

>  or because they are floppy-only or CD-only VMs with
> no hard disk).
>
> To enable savevm, at least according to docs, I have to have a qcow2
> image somewhere.  So I add a redundant minimum-size unpartitioned
> qcow2 hard disk and hope nobody minds...
>
> That seems a bit hackish.  It would be nice if savevm could just write
> to a named file and loadvm could read it.
>   

I'm in the process of cleaning up the live migration code from KVM for 
QEMU.  It works quite happily right now, I'm just reorganizing some things.

In the process, I hope to introduce a checkpoint command which provides 
a live snapshotting mechanism.  I think there is certainly room for 
discussion about whether you should be able to snapshot/savevm to a file 
besides snapshotting to a qcow2 file.

I think snapshotting to a pipe is actually a really interesting use-case 
myself for a variety of applications.

Regards,

Anthony Liguori

> -- Jamie
>
>
>