Use Your Own ISO/USB Images
While "Linux" is arguably the typical operating system for cloud servers, detailed preferences can be quite diverse. At cloudscale.ch, you benefit on the one hand from a wide range of images of popular Linux distributions, while on the other hand you can use a small trick to also install almost any other system – and much more.
Reasons to use your own image
In addition to many popular Linux distributions, cloudscale.ch also offers a choice of two firewall distributions when starting a new server. You may, however, prefer a different distribution, e.g. for personal considerations, or to keep your new system as similar to existing ones as possible. By using your individual ISO/USB image, you can install almost any operating system at cloudscale.ch.
You can, however, do even more when using your own image: even if you choose to use Ubuntu, Debian or one of the other operating systems we offer, you have complete control over the initial setup. You can customize the partitioning, use your preferred file system or set up your own disk encryption (in addition to measures on our side). Furthermore, a live image can help to restore access to a crashed system after a mishap. And if required, you can create a consistent, sector-by-sector copy of your servers on an additional volume.
How to use your own images
As a starting point, you need a working server in the relevant cloudscale.ch account, to which you then attach an additional SSD volume with sufficient space for your ISO/USB image. This can be the server that you are going to reinstall with your favorite system, or just a temporary server that is used for the next step. Next, download your image to this server (e.g. using
wget) and subsequently copy the image, block by block, to the additional volume:
sudo dd if=my-own-image.iso of=/dev/vdb bs=1M && sync
Caution: It is important that you make absolutely certain that
of (output file) is pointing to your additional volume as this path will be overwritten without further warning!
If you want to use the image to boot a server other than the current one, reattach the volume to the desired server now. Then open the VNC console of the target server and restart it. By pressing "Esc" in the VNC console, you get to the boot menu, where the additional volume with your image appears as an extra "Virtio disk". Select it to start booting from your image. You can now use your image as you would a physical server and a DVD.
NB. If keystrokes appear multiple times in the VNC console, simply change "vnc_lite.html" to "vnc.html" in your browser's address bar (and click "Connect").
Some additional notes
After the target server has been installed or repaired, reboot it normally from its root volume. You can either delete the additional volume containing your image or keep it for future use.
The approach described in this article works with many images provided by the distributions for CDs/DVDs (.iso files) or for USB sticks, e.g. with Ubuntu and CentOS. However, cloudscale.ch cannot guarantee that it will work with a particular image.
Please note that the images provided by us for launching servers contain the "cloud-init" package. This package ensures correct configuration of your servers, e.g. by transferring the specified server name and the authorized SSH keys into the server's configuration. If you (re)install your server via a custom image, you will need to specify these settings manually. For the network details, you can either use DHCP or statically configure the details shown in the control panel.
Irrespective of whether you only have to fix a small mishap or need to build up an individual server farm "from scratch", by using your own ISO/USB images, you have full control over the software and configuration of your servers in all circumstances.
Has the right tools,
Your cloudscale.ch team