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 > > _______________________________________________ > libvirt-users mailing list > libvirt-users@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/libvirt-users _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
