2:32 a.m.
On Wed, Jun 14, 2017 at 10:26:09AM +0200, Dominik Psenner wrote:
Hi,
I'm investigating a performance issue on a virtualized windows server host
that is run on a ubuntu machine via libvirt/qemu. While the host can easily
read/write on the raid drive with 100Mmb/s as observable with dd, the
virtualized windows server running on that host is barely able to read/write
with at most 8Mb/s and averages around 1.4Mb/s. This has grown to the extent
that the virtualized host is often unresponsive and even unable to start up
its services with system default timeouts. Any help to improve the situation
is greatly appreciated.
Just to provide some even weirder numbers.
With Debian on bare metal hosting Debian VM by qemu, kvm, for the
I/O model comparison, I found there were about
40% performance drop (read), 26K(transaction/s) to 15 K (transaction/s)
in pbench switching from IDE to virtio; while 18 K for bare metal.
There would be 0 % to 70 % improvement in apache bench (request/s) depending
on concurrency level, switching from IDE-e1000 to virtio-virtio.
Very likely something was seriously wrong, as I expected when I/O bound,
virtio would have been the winner.
Dan
This is the configuration of the virtualized host:
~$ virsh dumpxml windows-server-2016-x64
<domain type='kvm' id='1'>
<name>windows-server-2016-x64</name>
<uuid>XXX</uuid>
<memory unit='KiB'>2097152</memory>
<currentMemory unit='KiB'>2097152</currentMemory>
<vcpu placement='static'>2</vcpu>
<resource>
<partition>/machine</partition>
</resource>
<os>
<type arch='x86_64'
machine='pc-i440fx-xenial'>hvm</type>
<boot dev='hd'/>
</os>
<features>
<acpi/>
<apic/>
<hyperv>
<relaxed state='on'/>
<vapic state='on'/>
<spinlocks state='on' retries='8191'/>
</hyperv>
</features>
<cpu mode='custom' match='exact'>
<model fallback='allow'>IvyBridge</model>
<topology sockets='1' cores='2' threads='1'/>
</cpu>
<clock offset='localtime'>
<timer name='rtc' tickpolicy='catchup'/>
<timer name='pit' tickpolicy='delay'/>
<timer name='hpet' present='no'/>
<timer name='hypervclock' present='yes'/>
</clock>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>restart</on_crash>
<pm>
<suspend-to-mem enabled='no'/>
<suspend-to-disk enabled='no'/>
</pm>
<devices>
<emulator>/usr/bin/kvm-spice</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' cache='none'/>
<source
file='/var/data/virtuals/machines/windows-server-2016-x64/image.qcow2'/>
<backingStore/>
<target dev='hda' bus='ide'/>
<alias name='ide0-0-0'/>
<address type='drive' controller='0' bus='0'
target='0' unit='0'/>
</disk>
<disk type='file' device='cdrom'>
<driver name='qemu' type='raw'/>
<source
file='/var/data/virtuals/machines/windows-server-2016-x64/dvd.iso'/>
<backingStore/>
<target dev='hdb' bus='ide'/>
<readonly/>
<alias name='ide0-0-1'/>
<address type='drive' controller='0' bus='0'
target='0' unit='1'/>
</disk>
<controller type='usb' index='0' model='ich9-ehci1'>
<alias name='usb'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x05'
function='0x7'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci1'>
<alias name='usb'/>
<master startport='0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x05'
function='0x0' multifunction='on'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci2'>
<alias name='usb'/>
<master startport='2'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x05'
function='0x1'/>
</controller>
<controller type='usb' index='0' model='ich9-uhci3'>
<alias name='usb'/>
<master startport='4'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x05'
function='0x2'/>
</controller>
<controller type='pci' index='0' model='pci-root'>
<alias name='pci.0'/>
</controller>
<controller type='ide' index='0'>
<alias name='ide'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x01'
function='0x1'/>
</controller>
<interface type='bridge'>
<mac address='52:54:00:0e:f2:23'/>
<source bridge='br0'/>
<target dev='vnet0'/>
<model type='rtl8139'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
</interface>
<serial type='pty'>
<source path='/dev/pts/1'/>
<target port='0'/>
<alias name='serial0'/>
</serial>
<console type='pty' tty='/dev/pts/1'>
<source path='/dev/pts/1'/>
<target type='serial' port='0'/>
<alias name='serial0'/>
</console>
<input type='tablet' bus='usb'>
<alias name='input0'/>
</input>
<input type='mouse' bus='ps2'/>
<input type='keyboard' bus='ps2'/>
<graphics type='vnc' port='5900' autoport='yes'
listen='127.0.0.1'>
<listen type='address' address='127.0.0.1'/>
</graphics>
<video>
<model type='vga' vram='16384' heads='1'/>
<alias name='video0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x02'
function='0x0'/>
</video>
<memballoon model='virtio'>
<alias name='balloon0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x04'
function='0x0'/>
</memballoon>
</devices>
<seclabel type='dynamic' model='apparmor' relabel='yes'>
<label>libvirt-XXX</label>
<imagelabel>libvirt-XXX</imagelabel>
</seclabel>
</domain>
Cheers,
Dominik
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