Re: [Qemu-devel] Re: [kvm-devel] [RFC][PATCH] Modify loop device to be able to manage partitions of the image disk

[Laurent Vivier <Laurent.Vivier@bull.net>]

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Le mardi 15 janvier 2008 à 18:27 +0000, Daniel P. Berrange a écrit :
> On Tue, Jan 15, 2008 at 07:22:53PM +0100, Laurent Vivier wrote:
> > As it should be useful to be able to mount partition from a 
> > disk image, (and as I need a break in my bug hunting) I've 
> > modified the loop driver to mount raw disk image.
> > 
> > To not break original loop device, as we have to change minor 
> > numbers to manage partitions, a new parameter is added to the module:
> 
> I don't see the point in modifying the loop device driver when you
> can already access the partitions with existing device mapper
> functionality & tools.

There are two reasons:

1- I didn't know kpartx (thank you for the tip)

but using loop device, you will be able to use all partition tables
known by the kernel (acorn,  atari,  efi,  karma,  mac, osf, sun,
ultrix, amiga, ibm, ldm, msdos, sgi, sysv68), whereas kpartx can use
only partition tables it knows (bsd, dasd, dos, mac, sun, efi, sun,
unixware).

2- I'd like to mount qcow2 or others disk image formats, so perhaps it's
easier to modify loop device driver (but perhaps you know another magic
tool ?)

Regards,
Laurent
-- 
----------------- Laurent.Vivier@bull.net  ------------------
  "La perfection est atteinte non quand il ne reste rien à
ajouter mais quand il ne reste rien à enlever." Saint Exupéry

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