Re: [Qemu-devel] qcow2 corruption observed, fixed by reverting old change

[Jamie Lokier <jamie@shareable.org>]

Kevin Wolf wrote:
> Jamie Lokier schrieb:
> > Although there are many ways to make Windows blue screen in KVM, in
> > this case I've narrowed it down to the difference in
> > qemu/block-qcow2.c between kvm-72 and kvm-73 (not -83).
> 
> This must be one of SVN revisions 5003 to 5008 in upstream qemu. Can you
> narrow it down to one of these? I certainly don't feel like reviewing
> all of them once again.

That's helpful, thanks.  It's a production mail server which was
affected, and it's being used at the moment.  Not sure if I can narrow
it down that easily :-)

> Do I understand correctly that your image fails with the kvm-73 version
> of block-qcow2.c and afterwards boots with kvm-72? So the image is not
> really corrupted but it's more likely an IO error which brings the OS down?

That's correct, it's always booted when trying again with kvm-72, or a
later kvm with block-qcow2.c reverted.

It might be an I/O error rather than corruption.  Up to kvm-76, I/O
errors aren't reported over the IDE driver.

-- Jamie