Re: [user question] Opinions about running Windows in KVM

[Paolo Bonzini <pbonzini@redhat.com>]

Il 16/12/2012 19:55, Andrew Cathrow ha scritto:

>> After the install and the resulting patch orgy finished, I noticed
>> that the KVM-based Windows install was running much slower than an
>> existing Windows 7 guest running under VirtualBox (on the same
>> hardware and a similiarly configured VM), which is odd since
>> sparkling new Windows installs usually tend to run much better than
>> an
> 
> Where you using virtio-blk or emulated IDE? 

Also, if you're using virtio-blk, can you cut-and-paste the libvirt XML?
 Check that it does not have cache='writethrough'.

Paolo


> 
> 
>> install that has been used for months. A few benchmarks showed that
>> the KVM-based Windows suffers from I/O performance that is almost an
>> order of magnitude slower than the one running based on VirtualBox.
>>
>> I would like to know whether I did something wrong, or if there is
>> another way to achieve compareable I/O performance in a Windows VM on
>> KVM than it is reachable with a trivial VirtualBox installation.
>>
>> On another point: The VirtualBox graphics drivers for Windows have an
>> option to couple the Windows desktop size to the size of the guest
>> Window. That is, when I resize the X11 Window that shows the VM
>> desktop, the desktop is automatically resized to fill the window
>> completely.
> 
> Try using spice with the windows guest tools which will give you copy and paste, cursor handling, resolution matching etc.
> http://www.spice-space.org/download.html
> 
>>
>> On KVM, I understand that the canonical way to run Windows in a VM is
>> to use the graphics drivers from VMWare as the graphics card emulated
>> by qemu-kvm is VMWare compatible. But it looks like this doesn't work
>> since Windows claims to have a "Standard VGA graphics adapter" which
>> is rather slow and only offers a list of standard screen resolutions
>> which also does not adapt to window size. I guess this is an issue
>> that I better address on a LibVirt mailing list, right?
>>
>> I would appreciate any comments, and - if appropriate - pointers to
>> other mailing lists that may help with getting Windows 7 to run
>> better
>> under KVM.
>>
>> Greetings
>> Marc
>>
>> --
>> -----------------------------------------------------------------------------
>> Marc Haber         | "I don't trust Computers. They | Mailadresse im
>> Header
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>> 31958061
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>> 31958062
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