Re: [Qemu-devel] PATCH: Control over drive open modes for backing file

[Anthony Liguori]

Jamie Lokier wrote:
> Anthony Liguori wrote:
>   
> > > Can I arbitrarily branch off different snapshots within a single qcow2
> > > file?  Can I delete the 'base' snapshots safely?  Most important: what
> > > happens if I have snapshots in a qcow2 file which has a base file, and
> > > I type 'commit'?  Does it corrupt all the snapshots, effectively?
> > >       
> > snapshots are linear, not branching.  And they are only every 
> > saved/loaded from the highest level qcow2 file.
> >     
>
> So if I understand that right, the 'commit' command (to write to the
> base image) _will_ corrupt all the snapshots since they depend on the
> base image and it just changed??
>   

Yes, so don't do that.

BTW, commit is a pretty useless command IMHO.  If you use it to save a 
snapshot of a disk image while the OS has it mounted, you're not getting 
a very good backup.

Regards,

Anthony Liguori

Regards,

Anthony Liguori

> -- Jamie
>
>
>