Having build my own NAS system recently, I realised I do not have any monitors or keyboards at home anymore. Hence installing Debian will be hard.
I looked around and the solution would be a headless install via ssh.
This post is based on some work from S.G. Vulcan’s post Installing Debian using only SSH
His post was a good start, but I only could make it work for a Debian Jessie netinstall image after some changes.
So what is the solution
Download the latest netinstall image from Debian, I used debian-8.3.0-amd64-netinst.iso
Mount the ISO to a folder
Copy to new folder called isonew
Change the menu to load SSH on boot by default, edit isonew/isolinux/txt.cfg remove (if existing) menu default from label install and add:
Create isonew/preseed.cfg file. I adapted the locale and keyboard settings for Germany and added the selection of the keyboard-configuration. This would otherwise be an open question during the install and we won’t reach the SSH startup.
Also I added a check for non-free firmware, which popped up on one of my machines which had wireless.
Recreate the isonew/md5sum.txt, it is read only, so you need to change this. Also I had better luck with creating the md5sum.txt with the changed commands below.
Create ISO file to burn with xorriso. If you do not have it installed use apt-get install xorriso.
xorriso is creating a correct partition table, which is for some reason not done with mkisofs only. The original command would work in VMs, maybe even on a cd-rom, however not for USB sticks.
The ISO can be burned to an USB stick and used to boot. It will automatically configure the network with DHCP (yes, you need to have a way to find the IP, e.g. on your router) and start SSH.
The user for the ssh connection is installer the password is install.