If you want to install an own image, for example to prepare your own partition set, you can do without a hardware KVM over IP for few operating systems. It is required to have at least 4 GB of memory, to save the ISO image to the memory.
First of all, set your server to rescue mode via the central customer management interface ( https://customer-interface.com ) and connect to it via SSH ( for example with Putty ).
Now install "kvm" with the following command:
apt-get update && apt-get update && apt-get upgrade && apt-get install kvm
Possibly you will have to load the correct kernel module, for intel processors "kvm-intel" and for amd processors use "kvm-amd". For older systems the both modules may not work, you can use "kvm" module in this case, but it is much slower than the other modules.
After you installed the application, you will have to create a temporary partition within the memory, to store the installation image there.
mount -ttmpfs -osize=2G tmpfs /tmp
After this, download your ISO image to /tmp/image.iso .
wget -O /tmp/image.iso http://www.link-zum-iso.de/some.iso
Now check which drives are available in your system, so that you know what to pass to KVM.
# parted -l | grep "Disk "
Disk /dev/sda: 500GB
Disk /dev/sdb: 500GB
Now start your KVM ( Kernel based Virtual Machine ):
kvm -enable-kvm -hda /dev/sda -hdb /dev/sdb -m 1024 -vnc :0 -cdrom /tmp/image.iso -boot d
The KVM is now started, to perform the necessary steps of the installation, connect to your server via VNC ( for example with TightVNC http://www.tightvnc.com/ ). You should now see the installation process, finish all steps and then shutdown the server, but only within the KVM ( in the VNC connection ). Don't forget to set up your network configuration before shutting down. When finished, stop the rescue mode, wait a few minutes and trigger the reset for the affected server, so that it can boot in normal mode.
Please also notice that this method won't work for all operating systems, explicitly virtualization systems like VMware will probably not work when installed like this.For Windows guests don't forget to install the necessary drivers for the main board / nic.