[libvirt] [ANNOUNCE] virt-df 2.1.0 - a 'df' tool for virtual guests

[Daniel P. Berrange]

On Thu, May 15, 2008 at 07:53:55PM +0100, Richard W.M. Jones wrote:
> On Thu, May 15, 2008 at 02:54:53PM +0100, Daniel P. Berrange wrote:
> > > This version supports most common filesystems and partitioning
> > > schemes, including:
> > >  - Linux ext2/3
> > >  - DOS FAT32
> > >  - Windows NTFS
> > >  - Linux LVM2 (volume groups and logical volumes)
> > >  - Primary and extended disk partitions
> > >  - Linux swap
> > >  - Linux suspend partition
> > 
> > I'm assuming this only works for raw file & block devices ? Are you planning
> > to support the funky QCow / VMDK formats too ?
> 
> Yes, interesting point.  Since I always use flat files or straight
> partitions for my guests I admit I hadn't given this much thought :-)
> However support for these formats is just a matter of decoding enough
> of the structure to enable the same mappings to be made in the
> 'virt-df' library, same as for LVM2 or indeed MBR partitions now.
> 
> I'll take a look at it.  IIRC there are several different undocumented
> variations on the QCow format?

There's version 1, and version 2.

And then the incompatible version 2 inflicted by Xen :-(

> > The other thing that could be annoying is that Fedora 9 support for
> > encrypting all volumes - might need to prompt for a decryption key
> > for that.
> 
> Yes -- any encrypted volumes aren't going to work at the moment, and
> couldn't work unless there was a way to access the passphrase.

The passphrase is in the user's brain. THe OS prompts for it at boot time,
so virt-df would need todo similar if it wanted to support decryption.
Perhaps its just not a important use case. In the ISP model, guest admins
won't trust the host admin so you won't have the keys anyway. If the guest
admin does trust the host admin, would they really be using encryption
in the guest ?

Dan.
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