I've always been a fan of the flexibility of anaconda and kickstart not just for installing systems, but also for rescuing a system when something goes horribly wrong. Yesterday I updated a remote test system from Fedora 16 to Rawhide, and I found myself with no network access to the machine due to a
firmware issue. The system has DRAC 6 express, so I can reset the system and force a pxe boot, but I can't see or interact with the console when it boots. Recent Fedora releases have a great way to rescue a system in this state. First, you set up a kickstart file for the rescue (probably only the first two lines are needed, but I did not test with fewer lines than this):
rescue --nomount
sshpw --username=root sekrit --plaintext
url --url http://mirror.eucalyptus/fedora/releases/16/Fedora/x86_64/os/
lang en_US.UTF-8
firewall --enabled --port=22:tcp
Then set up these boot options in your PXE configuration:
ks=http://yourWebServer/ks/fedora-16-rescue.cfg ksdevice=link keymap=us lang=en_US sshd
This works just like rescue mode always has, except you don't need console access. Very cool.
I'm sure this feature isn't news to a lot of Fedora users, but sometimes cool new features like this sneak into a Fedora release and not everyone realizes it, so it seemed to be worth a quick blog.
