Re: qcow2 corruption?

Ryan Harper
2009-01-09T13:34:53Z

* John Morrissey <jwm@horde.net> [2009-01-08 21:44]:
> On Thu, Jan 08, 2009 at 02:33:28PM -0600, Anthony Liguori wrote:
> > John Morrissey wrote:
> > >I'm encountering what seems like disk corruption when using qcow2 images,
> > >created with 'kvm-img create -f qcow2 image.qcow2 15G'.
> > >
> > >A simple test case is to use the Debian installer (I'm using the lenny
> > >rc1 images from http://www.debian.org/devel/debian-installer/) to install
> > >a new domain. The qcow2 file on disk grows due to the mkfs(8) activity,
> > >then the installer faults while trying to mount the root filesystem
> > >(Invalid argument). 'fdisk -l' shows that the partition table just
> > >created by the installer is gone.
> >
> > There are patches that touch the block layer. Please try to reproduce
> > on vanilla kvm. I don't trust the debian patches.
>
> Couldn't reproduce this with Debian packaging minus its patch for
> CVE-2008-0928 (taken from Fedora FWIW), which is the only one touching the
> block layer.
>
> Upon further scrutiny, I realized I pooched updating the patch for KVM 82.
> The value for the BDRV_O_AUTOGROW constant introduced in that patch collides
> with a new BDRV_ constant introduced between KVM 79 and 82. Changing the
> constant's value (Fedora project has an updated patch, too) fixes this.
>
> Ryan, this seems to fix the SCSI BUGging, too. I figure you won't want to
> pursue that further?

excellent! I had seen the error before but only while developing some
new code for the scsi device, so it was a little surprising to see. If
you can't recreate now, I think we're done. =)

>
> Sorry for the bother, guys.

np, thanks for testing.

--
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
ryanh@us.ibm.com