Re: [Qemu-devel] [Bug 816860] [NEW] Guest machine freezes when NFS mount goes offline

[Stefan Hajnoczi]

On Wed, Jul 27, 2011 at 10:09 AM, Igor Blanco <address@hidden> wrote:
> Public bug reported:
>
> I have a virtual KVM machine that has 2 CDROM units with ISOs mounted
> from a NFS mount point. When NFS server goes offline the virtual machine
> blocks completely instead of throwing read errors for the CDROM device.
>
> Host: Proxmox VE 1.8-11 (Debian GNU/Linux 5.0)
> KVM commandline version: QEMU emulator version 0.14.1 (qemu-kvm-devel)
> Guest: Windows 7 professional SP 1

Thanks for reporting this.  There are instances where QEMU performs
blocking operations in a thread that will prevent the guest from
running.  I suspect you are hitting this case and refactoring work
needs to be done to ensure that QEMU threads never block.

Stefan