User FAQ

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FAQs for new users

I'm new to FAI. How should I start ?

  • Use the FAI CD and the FAIme build service
  • Install the stable distribution on your first clients!

Where do I find the log files?

  • During installation the are available in /tmp/fai/ on the install client
  • At the end of the installation they will be copied to /target/var/log/fai
  • If $LOGSERVER and $LOGUSER are set, they are copied to the install server in the home directory of the user $LOGUSER
  • After rebooting the install client, the are available in /var/log/fai

Somewhat more advanced FAQs

Can I write a hook that is executed after a certain task?

(freely) quoting #fai:

<sanso> is there a way to define post-hooks other than defining a (pre-)hook for the following task?
<Mrfai> sanso: yes post hooks are possible. Define a pre hook, and inside this hook, you 
first call the default task using task_taskname, then add your code for the post hook. 
And don't forget to call skiptask.
Mmmm, do you like to add this to the faiwiki, maybe a FAQ or tip?

More technical stuff / troubleshooting

I try to install testing or sid/unstable and something goes wrong. Why?

testing and unstable sid change every day. So it's possible that your problems are solved today or tomorrow. You should try again. It's recommendable to use a local mirror and freeze it when you found a working install. But we also recommend to use stable and local backport repositories whenever possible.

As for sid - that's why it's called unstable You might want to get used to things braking.

You should only try to install unstable or testing if You know what you're doing and You know You definitely need something other than stable

sanso 10:20, 11 Aug 2005 (CEST)

What order are scripts executed in?

Scripts are executed in class definition order, and in numerical order within each class.

For example, if the classes FOO and BAR were defined (in that order), and $FAI_CONFIGDIR/scripts/FOO contained 20-foo and 40-bar, and $FAI_CONFIGDIR/scripts/BAR contained 30-mycode, the order of execution would be:

  1. $FAI_CONFIGDIR/scripts/FOO/20-foo
  2. $FAI_CONFIGDIR/scripts/FOO/40-bar
  3. $FAI_CONFIGDIR/scripts/BAR/30-mycode

Why does the system reboot after entering ctrl-c following an installation?

The default actions for FAI do not allow you to get a shell since it is insecure and it will reboot on <ctrl-c> by design.

If you want to get a shell you need to change FAI's actions by adding 'createvt' to the FAI_FLAGS variable that is passed to the kernel on startup. You can do this via fai-chboot (e.g. fai-chboot -iFv -k "FAI_ACTION=install" hostname) for network installs.

Why can't I login via ssh to my install client(s) anymore? It used to work but suddenly stopped working.

After you have reinstalled FAI on your server a new ssh host key is generated. This also happens when you call fai-setup or fai-make-nfsroot. Remove the relevant line from ~/.ssh.known_hosts and try again. You can use ssh-keygen -R for removing a host from the known_hosts file.

I need a /boot partition, how do I create one?

If your disk is larger than your BIOS can handle, you will need to create a boot partition to boot from. If you don't have a boot partition you will get GRUB Error: 18 when the client boots [1]. Use a disk_config like this one to boot from the /boot partition:

disk_config disk1
primary     /boot           100         rw              ; ext2 boot 
logical     /               5000        rw              ; -j ext3
logical     swap            100-400     rw              

It is important that only the /boot partition is primary, that its filesystem is ext2 and that the boot option is set. If not, FAI will assume that the root partition (/) is the boot partition and GRUB will try to boot from that one. It will result in GRUB Error 15.

Device missing or not a block device - where did my device go?

If Rebooting fails because of modules missing (e.g. can't mount root fs ...) Chances are in error.log You'll find a line saying

rcS.log:Failed to create initrd image.

rcS.log says:

Setting up kernel-image-2.6.8-2-686-smp (2.6.8-12) ...
/usr/sbin/mkinitrd: device /dev/sda1 is not a block device
Failed to create initrd image.

I modified Steffen Grunewald's script:

Yes. udev is the culprit, [...] As a workaround, you may set up a hook for configure,

e.g. in $CONFIGSPACE/hooks/configure.DEFAULT

echo $0 udev bug workaround
# work-around for udev bug
if [ -x $target/etc/init.d/udev ]; then
   chroot $target /etc/init.d/udev stop
   chroot $target /usr/bin/dpkg --configure --pending
   chroot $target /etc/init.d/udev start