Re: Virtual SCSI disks hangs on heavy IO

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, Mar 14, 2011 at 10:57 PM, Guido Winkelmann
<guido-kvml@xxxxxxxxxxxxxxxxx> wrote:
> On Monday 14 March 2011 20:32:23 Stefan Hajnoczi wrote:
>> On Mon, Mar 14, 2011 at 6:05 PM, Guido Winkelmann
>>
>> <guido-kvml@xxxxxxxxxxxxxxxxx> wrote:
>> > Does anybody have an idea what might cause this or what might be done
>> > about it?
>>
>> The lsi_scsi emulation code is incomplete.  It does not handle some
>> situations like the ORDERED commands or message 0x0c.
>>
>> There is a patch to address the message 0xc issue, it has not been
>> applied to qemu.git or qemu-kvm.git yet:
>> http://patchwork.ozlabs.org/patch/63926/
>>
>> Basically there is no one actively maintaining or reviewing patches
>> for the lsi53c895a SCSI controller.
>
> Does that mean that using the SCSI transport for virtual disks is officially
> unsupported or deprecated or that it should be?

The LSI SCSI emulation in particular has not seen much attention.  As
for the wider SCSI emulation there has been work over the past few
months so it's alive and being used.

> Are things better with the IDE driver?

IDE is commonly used for compatibility with guests that do not have
virtio-blk drivers.  It should work fine although performance is poor
due to the IDE interface.

>> virtio-blk works very will with Linux guests.  Is there a reason you
>> need to use SCSI emulation instead of virtio-blk?
>
> I can probably use virtio-blk most of the time, I was just hoping to be able
> to virtualize a wider array of operating systems, like the *BSDs,
> (Open)Solaris, Windows, or even just some linux distributions whose installers
> don't anticipate KVM and thus don't support virtio-<anything>.

Windows virtio-blk drivers are available and should be used:
http://www.linux-kvm.org/page/WindowsGuestDrivers/Download_Drivers

BSD and Solaris don't ship with virtio-blk AFAIK.

Stefan
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux