KVM Windows Guests

QEMU/KVM Windows Guests installation and management examples

NB! Only virtio drivers provide acceptable disk/network IO levels - so you should use them!
NB! At the moment we are standardized on using QCow2 image format - using ‘preallocation=metadata’ option provides better speed - so disk metadata preallocation is highly suggested!
Windows Server 2008R2

virt-manager ISO install

Enter VM hostname
Choose local install media

Enter ISO path or click on ‘Browse’
Set correct OS type and version

If choosed to browse previously then click on local-iso pool and pick needed ISO file

Set VM memory
Set VM vCPUs

Create VM disk - default format is set in virt-manager preferences - we suggest to set it to qcow2

Leave ‘Customize configuration on’ - as we need to perform some changes still
Choose ‘Advanced Options’ -> Specify shared device name’ -> Bridge name: vmbr0
Click ‘Finish’

Choose Disk1
Set disk bus/driver to virtio

Choose NIC
Set NIC driver to Intel E1000

Choose ‘Add Hardware’ -> Storage
Add Windows virtio drivers ISO cdrom disk
Click ‘Finish’
Click ‘Begin Installation’

virt-install ISO install

# Place WinServ ISO into /storage/local/iso/
# Download VIRTIO driver iso image to use during install
cd /storage/local/iso/
wget http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/virtio-win-0.1-52.iso

# Pre-create VM disk image
qemu-img create -f qcow2 -o preallocation=metadata /storage/local/images/winserv1.qcow2 50G

# Launch installation inside screen
screen
virt-install --connect qemu:///system --name WinServ1 --ram 2048 --vcpus 2 \
--disk path=/storage/local/images/winserv1.qcow2,format=qcow2,bus=virtio,cache=none \
--disk path=/storage/local/iso/virtio-win-0.1-52.iso,device=cdrom \
--cdrom /storage/local/iso/winserv.iso \
--network=network:default,model=e1000 \
--vnc --os-type=windows --os-variant=win2k8 \
--noautoconsole --accelerate --noapic --keymap=en-us
# Detach screen
CTRL+A+D

# Run virt-manager for VNC display 
# (make sure you have X forwarding enabled on your ssh session for remote display)
virt-manager
# OR
virt-viewer WinServ1

# NB! After Windows installation please dont forget to remove the cdrom devices (live version)
virsh attach-disk WinServ1 '' hda --mode readonly --type cdrom
virsh attach-disk WinServ1 '' hdc --mode readonly --type cdrom

Windows installer wont find any disks until you load windows virtio drivers
Please browse drive E: (CDROM)
Choose WLH->AMD64 for 64bit Guest or WLH->X86 for 32bit Guest
Choose ‘Red Hat VirtIO SCSI controller’ and click ‘Next’
Pre-prepared disk should appear in installer

Install from VM template

# Get opennode TUI management menu
opennode

# Deploy QEMU/KVM template
# Choose 'Create VM' -> KVM -> Pick template -> Insert required parameters -> Hit 'Create VM'

# Set VM domain name (what you entered as VM hostname in TUI form)
VMDOMAIN=vmhostname

# Dump Guest Definition XML
virsh dumpxml $VMDOMAIN > /storage/local/images/$VMDOMAIN.xml

# Rewrite disk bus and other misc parts
sed -i "s/driver name='qemu' type='qcow2'/driver name='qemu' type='qcow2' cache='none'/" /storage/local/images/$VMDOMAIN.xml
sed -i "s/target dev='hda' bus='ide'/target dev='vda' bus='virtio'/" /storage/local/images/$VMDOMAIN.xml
sed -i "s/address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/" /storage/local/images/$VMDOMAIN.xml
sed -i "s/address type='drive' controller='0' bus='0' target='0' unit='0'/address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/" /storage/local/images/$VMDOMAIN.xml
sed -i "s/<clock offset='utc'\/>/<clock offset='localtime'><timer name='rtc' tickpolicy='catchup'\/><\/clock>/" /storage/local/images/$VMDOMAIN.xml
sed -i "/<source bridge='vmbr0'\/>/a\\      <model type='e1000'\/>" /storage/local/images/$VMDOMAIN.xml

# Import Guest Definition changes
virsh define /storage/local/images/$VMDOMAIN.xml

# Launch Guest VM
virsh start $VMDOMAIN

Manage Guest resources

Displaying Guest info

virsh dominfo WinServ1

Id:             20
Name:           WinServ1
UUID:           b25da21c-bdf6-12b1-466f-fb747c850bc2
OS Type:        hvm
State:          running
CPU(s):         2
CPU time:       195.4s
Max memory:     2097152 kB
Used memory:    2097152 kB
Persistent:     yes
Autostart:      disable
Managed save:   no

Enlarging Windows Guest disk

# Shut down Guest VM
virsh shutdown WinServ1
# Resize guest image 
qemu-img resize /storage/local/images/winserv1.qcow2 +5GB
# Boot up guest
virsh start WinServ1

Inside Windows launch ‘Computer Management’->’Disk Management’
Right-click on root volume and choose ‘Extend Volume’ from pop-up menu

Hot-Add vCPU

# Shutdown Guest for maxvcpu setting
virsh shutdown WinServ1

# Set vCPU limits in config file - applies after next reboot
virsh setvcpus WinServ1 --maximum 4 --config

# Boot-up the domain again
virsh start WinServ1

# Verify new vCPU limits
virsh vcpucount WinServ1

maximum      config         4
maximum      live           2
current      config         4
current      live           2

# vCPU hot-add (not persistent)
virsh setvcpus WinServ1 4 --live

Memory ballooning

Memory management

You can dynamically change the memory in a VM up to what its maximum memory setting is. Note that by default the maximum memory setting in a VM will always equal the amount of memory you specified when you created the VM with the ram parameter in virt-install.

So for example if you created a VM with 1 GB of memory, you can dynamically reduce this amount without having to shut down the VM. If you want to increase the memory above 1 GB, you will have to first increase its maximum memory setting which requires shutting down the VM first.

# Set current memory in kilobytes (1G example)
virsh setmem domain 1048576

# Set maximum available memory in kilobytes (2G example)
virsh setmaxmem domain 2097152

Guest Autostart

# Enable
virsh autostart WinServ1

# Disable
virsh autostart --disable WinServ1

Attach/Detach/Change CDROM/ISO

# NB! attach-disk wont work if disk xml definition has been removed from domain xml
virsh attach-disk WinServ1 /storage/local/iso/filename.iso hdc --type cdrom --mode readonly
# Change ISO
virsh attach-disk WinServ1 /storage/local/iso/another.iso hdc --type cdrom --mode readonly
# Detach ISO
virsh attach-disk WinServ1 '' hdc --mode readonly --type cdrom

# CDROM Device ADD
# We need inactive guest to re-add cdrom xml part - other methods wont work currently
virsh dumpxml WinServ1 > /storage/local/images/winserv1.xml
virsh shutdown WinServ1
# Add CDROM xml description part
<disk type='file' device='cdrom'>
  <driver name='qemu' type='raw'/>
  <source file='/storage/local/iso/virtio-win-0.1-52.iso'/>
  <target dev='hdc' bus='ide'/>
  <readonly/>
</disk>
# Refresh Guest Definition
virsh define /storage/local/images/winserv1.xml 
# Boot-up guest with cdrom attached
virsh start WinServ1

# Remove CDROM device (doesn't work on active domain for some unknown reason)
virsh shutdown WinServ1
virsh detach-disk WinServ1 hdc --persistent

Retrive block devices info from guest

# Get devices info
virsh qemu-monitor-command WinServ1 '{ "execute": "query-block"}'

{"return":[{"io-status":"ok","device":"drive-virtio-disk0","locked":false,"removable":false,"inserted":{"ro":false,"drv":"qcow2","encrypted":false,"file":"/storage/local/images/winserv1.qcow2"},"type":"unknown"},{"io-status":"ok","device":"drive-ide0-1-0","locked":false,"removable":true,"inserted":{"ro":true,"drv":"raw","encrypted":false,"file":"/storage/local/iso/virtio-win-0.1-52.iso"},"tray-open":false,"type":"unknown"}],"id":"libvirt-55"}

Create Guest template

# Shutdown Guest for template creation
virsh shutdown WinServ1
# If shutdown wont work then force
virsh destroy WinServ1

Troubleshooting

Guest shutdown wont work

Guest shutdown usually fails if users are still logged in. You have 2 choices:

Ensure that all users are logged out and better shutdown Windows inside the Guest
Execute ‘yum destroy domain’ - in order to force VM shutdown