KVM

Using VirtualBox and KVM together

Using VirtualBox and KVM together at the same server at the same time is NOT possible!!!

• http://swaeku.github.io/blog/2013/04/04/run-kvm-and-virtualbox-together/

Use VirtualBox

sudo service qemu-kvm stop
sudo service vboxdrv start

OR use KVM

sudo service vboxdrv stop
sudo service qemu-kvm start

Decide!

Migration from VirtualBox to KVM

This boils down to

1. having a lot of time
2. having a lot of free harddisk space
3. creating a clone of the vbox-machine with VBoxManage clonehd (this can take a looooong time!). Kloning is the easiest way of getting rid of snapshots of an existing virtual machine.
4. converting the images from vdi to qcow-format with qemu-img convert
5. creating and configuring a new kvm-guest
6. adding some fou to NAT with a qemu-hook (see next section)

• http://serverfault.com/questions/249944/how-to-export-a-specific-virtualbox-snapshot-as-a-raw-disk-image/249947#249947

To clone an image - on the same machine - you have to STOP kvm and start vboxdr (see above). Also be aware, that the raw-images take up a lot of space!

# The conversion can take some time. Other virtual machines are not accessible in this time
VBoxManage clonehd -format RAW myOldVM.vdi /home/vm-exports/myNewVM.raw
0%...

cd /home/vm-exports/
qemu-img convert -f raw myNewVM.raw -O qcow2 myNewVM.qcow

Cloning a Snapshot:

# for a snapshot do (not tested)
cd /to/the/SnapShot/dir
VBoxManage clonehd -format RAW "SNAPSHOT_UUID" /home/vm-exports/myNewVM.raw

Accessing services on KVM guests behind a NAT

This is done by editing a hook-script for quemu:

/etc/libvirt/hooks/qemu

I am referring to this article:

• http://systemdilettante.blogspot.de/2013/06/accessing-services-on-kvm-guests-behind.html

which ist mentioned in the libvirt wiki:

• http://wiki.libvirt.org/page/Networking#Guest_configuration

I installed the qemu-python script of the first article under ubuntu 12.04 LTS, which worked like expected.

So I can access a port in the virtualmachine-guest with the IP/Port of the host (!). From within the host, it is possible to reach the guest via it's real ip. I am using the virtio-Interface (performance).

Control NAT rules

iptables -nvL -t nat

Delete NAT rules

iptables -t nat -D PREROUTING 1

Backup KVM

Via LVM

• http://pof.eslack.org/2010/12/23/best-solution-to-fully-backup-kvm-virtual-machines
• http://sandilands.info/sgordon/automatic-backup-of-running-kvm-virtual-machines

LiveBackup

• http://wiki.qemu.org/Features/Livebackup