Problems booting FAI from network, problems mounting nfsroot

[Thomas Lange]

This mail explains some common problems with FAI >=3.2 which uses a
kernel with initrd and how to fix them.

- I you have problems booting FAI via kernel and initrd and mounting the
  nfsroot over NFS. Sometimes you even see the mount request on the
  NFS server.

- If you boot from fai-cd but do not use the nfsroot from CD but using
  root=/dev/nfs and ip=dhcp

- If you boot via PXE but did not create the pxelinux/cfg by using the
  command fai-chboot

- When (or after) trying to mount the nfsroot you see:
  short read 0<28. And the initrd tries to mount again and again

Read the messages on the console which scripts are executed.

This is WRONG:

Begin: Mounting root file system...
Begin: Running /scripts/nfs-top


Instead, you should see this:

Begin: Mounting root file system...
Begin: Running /scripts/live-premount


You should not see scripts with name nfs-* get executed, instead the
live-* script should be executed. Check the parameters that you've
appended to the kernel: 

Example (wrong):

kernel /boot/vmlinuz boot=live FAI_FLAGS="verbose,createvt" FAI_ACTION=sysinfo ip=dhcp root=/dev/nfs nfsroot=/srv/fai/nfsroot

Example (correct):

kernel /boot/vmlinuz root=/dev/nfs boot=live FAI_FLAGS="verbose,createvt" FAI_ACTION=sysinfo ip=dhcp nfsroot=/srv/fai/nfsroot


The order of the boot= and root= parameters are important, because
root=/dev/nfs also sets boot=nfs and so a previous boot=live
definition will be overwritten and the wrong script are executed.

This bug is present in the combination of initramfs-tool 0.85h and
live-initramfs 1.110.7~200711. 


BTW: You can debug problems inside the initrd, when you boot your
kernel and initrd and append break=mount as kernel parameter. Then you
will get the shell from initramfs before it tries to do the nfs
mount.

-- 
regards Thomas