[Qemu-devel] Windows Virtio Issue

[Qemu-devel] Windows Virtio Issue

[Paul Fisher]

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Dear Yan,

We seem to be having some trouble with virtio disk on Windows Server 2008
R2 running on qemu-kvm. Essentially, when disk IO is stressed, it seems to
blue screen.


These are potentially contended disks, since it's public cloud with
multiple customers on the host - the issue could be connected to contention
making disk response slow?

Pertinent facts:

* qemu-kvm 1.0

* Hosts have linux kernel 3.2.2, 64 bit, AMD Opteron 6128

* VM is Windows Server 2008 R2, 64 bit - all patches downloaded from MS

* Virtio disk drivers are the February 2012 release .2200. Problem is
apparent with the older .2000 driver as well.

* Blue screen shows failure in viostor.sys - screen cap and minidump are at
http://dl.dropbox.com/u/12332019/2200BSOD.zip


* Replication: Yes. Easily. In this case I stressed the disk by running
Crystal Disk mark (a free IO measuring tool). When it got to the 4 KB
random seek tests - I think it was on write - it would consistently blue
screen.

* If it would help, I can provide remote access to this virtual machine if
you wish - it's in our cloud system.

* qemu-kvm command line:


qemu-kvm -m MEMORY -smp SMP -cpu host -nodefaults -vga cirrus -vnc :1
-drive if=none,id=block.0,format=raw, cache=writeback,file=drive.img
-device virtio-blk-pci,bootindex=1,
drive=block.0 -monitor stdio

Any help would be greatly appreciated.

Regards,
Paul Fisher
Operations Manager
ElasticHosts Ltd

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Re: [Qemu-devel] Windows Virtio Issue

[Yan Vugenfirer]

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Hello Paul,

Vadim is the owner of virtio-block Windows driver. He will try to help you.

Best regards,
Yan.

On Mar 23, 2012, at 7:32 PM, Paul Fisher wrote:

> Dear Yan,
> 
> We seem to be having some trouble with virtio disk on Windows Server 2008 R2 running on qemu-kvm. Essentially, when disk IO is stressed, it seems to blue screen.
> 
> 
> These are potentially contended disks, since it's public cloud with multiple customers on the host - the issue could be connected to contention making disk response slow?
> 
> Pertinent facts:
> 
> * qemu-kvm 1.0
> 
> * Hosts have linux kernel 3.2.2, 64 bit, AMD Opteron 6128
> 
> * VM is Windows Server 2008 R2, 64 bit - all patches downloaded from MS
> 
> * Virtio disk drivers are the February 2012 release .2200. Problem is apparent with the older .2000 driver as well.
> 
> * Blue screen shows failure in viostor.sys - screen cap and minidump are at http://dl.dropbox.com/u/12332019/2200BSOD.zip
> 
> 
> * Replication: Yes. Easily. In this case I stressed the disk by running Crystal Disk mark (a free IO measuring tool). When it got to the 4 KB random seek tests - I think it was on write - it would consistently blue screen.
> 
> * If it would help, I can provide remote access to this virtual machine if you wish - it's in our cloud system.
> 
> * qemu-kvm command line:
> 
> 
> 
> qemu-kvm -m MEMORY -smp SMP -cpu host -nodefaults -vga cirrus -vnc :1  -drive if=none,id=block.0,format=raw, cache=writeback,file=drive.img -device virtio-blk-pci,bootindex=1,
> drive=block.0 -monitor stdio
> 
> Any help would be greatly appreciated.
> 
> Regards,
> Paul Fisher
> Operations Manager
> ElasticHosts Ltd


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Re: [Qemu-devel] Windows Virtio Issue

[Vadim Rozenfeld]

On Sunday, March 25, 2012 07:01:54 PM Yan Vugenfirer wrote:
Hi Paul,
Could you try reproducing this problem on "-smp 2" guest, with
small memory dump option turned on, instead of kernel memory dump.

Thanks,
Vadim.

> Hello Paul,
> 
> Vadim is the owner of virtio-block Windows driver. He will try to help you.
> 
> Best regards,
> Yan.
> 
> On Mar 23, 2012, at 7:32 PM, Paul Fisher wrote:
> > Dear Yan,
> > 
> > We seem to be having some trouble with virtio disk on Windows Server 2008
> > R2 running on qemu-kvm. Essentially, when disk IO is stressed, it seems
> > to blue screen.
> > 
> > 
> > These are potentially contended disks, since it's public cloud with
> > multiple customers on the host - the issue could be connected to
> > contention making disk response slow?
> > 
> > Pertinent facts:
> > 
> > * qemu-kvm 1.0
> > 
> > * Hosts have linux kernel 3.2.2, 64 bit, AMD Opteron 6128
> > 
> > * VM is Windows Server 2008 R2, 64 bit - all patches downloaded from MS
> > 
> > * Virtio disk drivers are the February 2012 release .2200. Problem is
> > apparent with the older .2000 driver as well.
> > 
> > * Blue screen shows failure in viostor.sys - screen cap and minidump are
> > at http://dl.dropbox.com/u/12332019/2200BSOD.zip
> > 
> > 
> > * Replication: Yes. Easily. In this case I stressed the disk by running
> > Crystal Disk mark (a free IO measuring tool). When it got to the 4 KB
> > random seek tests - I think it was on write - it would consistently blue
> > screen.
> > 
> > * If it would help, I can provide remote access to this virtual machine
> > if you wish - it's in our cloud system.
> > 
> > * qemu-kvm command line:
> > 
> > 
> > 
> > qemu-kvm -m MEMORY -smp SMP -cpu host -nodefaults -vga cirrus -vnc :1 
> > -drive if=none,id=block.0,format=raw, cache=writeback,file=drive.img
> > -device virtio-blk-pci,bootindex=1, drive=block.0 -monitor stdio
> > 
> > Any help would be greatly appreciated.
> > 
> > Regards,
> > Paul Fisher
> > Operations Manager
> > ElasticHosts Ltd

Re: [Qemu-devel] Windows Virtio Issue

[Paul Fisher]

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On 26 March 2012 09:50, Vadim Rozenfeld <vrozenfe@redhat.com> wrote:

> On Sunday, March 25, 2012 07:01:54 PM Yan Vugenfirer wrote:
> Hi Paul,
> Could you try reproducing this problem on "-smp 2" guest, with
> small memory dump option turned on, instead of kernel memory dump.
>
> Thanks,
> Vadim.
>
>

Hi Vadim.

Thank you kindly for getting back to me.

I can certainly do that:

Dump and BSOD are in a zip at
http://dl.dropbox.com/u/12332019/2200-VirtioBSOD-2.zip

This time running with 2 cores:

qemu-kvm -m 1024 -smp sockets=1,cores=2 -cpu host -nodefaults -vga cirrus
-vnc :1  -drive if=none,id=block.0,format=raw,
cache=writeback,file=drive.img -device
virtio-blk-pci,bootindex=1,drive=block.0 -monitor stdio

Same procedure to get it to break - run crystal disk mark. Passed the
stream read/write and 512k block read/write - broke at the seek intensive
4k level.

Regards,
Paul

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Re: [Qemu-devel] Windows Virtio Issue

[Vadim Rozenfeld]

On Monday, March 26, 2012 02:45:34 PM Paul Fisher wrote:
> On 26 March 2012 09:50, Vadim Rozenfeld <vrozenfe@redhat.com> wrote:
> > On Sunday, March 25, 2012 07:01:54 PM Yan Vugenfirer wrote:
> > Hi Paul,
> > Could you try reproducing this problem on "-smp 2" guest, with
> > small memory dump option turned on, instead of kernel memory dump.
> > 
> > Thanks,
> > Vadim.
> 
> Hi Vadim.
> 
> Thank you kindly for getting back to me.
> 
> I can certainly do that:
> 
> Dump and BSOD are in a zip at
> http://dl.dropbox.com/u/12332019/2200-VirtioBSOD-2.zip
> 
> This time running with 2 cores:
> 
> qemu-kvm -m 1024 -smp sockets=1,cores=2 -cpu host -nodefaults -vga cirrus
> -vnc :1  -drive if=none,id=block.0,format=raw,
> cache=writeback,file=drive.img -device
> virtio-blk-pci,bootindex=1,drive=block.0 -monitor stdio
> 
> Same procedure to get it to break - run crystal disk mark. Passed the
> stream read/write and 512k block read/write - broke at the seek intensive
> 4k level.
> 
> Regards,
> Paul

Hi Paul,
Managed to reproduce this problem, thank you. Going to fix it in the build.
Meanwhile, instead of writeback, could you  try cache=off ?

Best regards,
Vadim.

Re: [Qemu-devel] Windows Virtio Issue

[emilien]

Vadim Rozenfeld <vrozenfe <at> redhat.com> writes:

> Hi Paul,
> Managed to reproduce this problem, thank you. Going to fix it in the build.
> Meanwhile, instead of writeback, could you  try cache=off ?
> 
> Best regards,
> Vadim.
> 
> 

Any news?
I have the same issue with cache=off, there isn't any fix?

Best regards,

Emilien