Building a live ISO

How to turn the FAI nfsroot into a file system for diskless clients

Someone asked me about using the FAI nfsroot for a diskless client setup. The clients should PXE boot and have /tmp and /var as tmpfs (means writable).

It's pretty easy. (Tested with FAI 4.1 and dracut 034-2 (wheezy) and with FAI 4.4~beta and dracut 40-1 (jessie)).

First add all packages you like to have for your diskless clients to /etc/fai/NFSROOT.

Create the FAI nfsroot

fai-make-nfsroot -v

Then disable some FAI specific things inside the nfsroot:

chroot /srv/fai/nfsroot bash
rm -f /etc/init.d/rcS
dpkg-divert --package fai-nfsroot --remove --rename /etc/init.d/rcS
insserv -r fai-abort
exit

This also works with XFCE and xorg running a graphical desktop.

That's it. Now, boot your client. Since FAI is using aufs (advanced multi layered unification filesystem version 3.x), the whole filesystem is writeable for the client, even it's mounted read-only.