fai 4.0.5: dracut boot ends with kernel panic

[Nicolas Courtel]

Hello,

I'm trying to use dracut in FAI 4.0.5 on a wheezy 64bits server, and the 
initial boot on nfsroot quickly goes into kernel panic:

[   11.578824] dracut: Mounted root filesystem 
a.b.c.d:/srv/fai/wheezy/nfsroot-amd64
[   11.581213] aufs: module is from the staging directory, the quality 
is unknown, you have been warned
[   11.582117] aufs 3.2-20120827
warning: can't open /etc/fstab: No such file or directory
[   12.010629] aufs test_add:261:mount[366]: uid/gid/perm /live/image 
65534/65534/0755, 0/0/01777
[   12.015811] type=1702 audit(1358959337.356:2): op=follow_link 
action=denied pid=371 comm="ls" path="/sysroot/initrd.img" dev="aufs" 
ino=149
[   12.015995] type=1702 audit(1358959337.356:2): op=follow_link 
action=denied pid=371 comm="ls" path="/sysroot/vmlinuz" dev="aufs" ino=165
/init: 42://lib/dracut/hooks/pre-pivot/50mount-usr.sh: cannot open 
/sysroot/etc/fstab: No such file
[   12.260523] dracut: Switching root
  pcbind: rpcbind terminating on signal. Restart with "rpcbind -u"
switch_root: failed to execute /sbin/init: Not a directory
[   12.262090] Kernel panic - not syncing: attempting to kill init!


nfsroot has been successfully built using fai-chboot -SFv, and only 
contains an empty /etc/fstab, and no /sysroot directory or link.

I initially thought that the problem was caused by nfs4 use of 
nobody:nogroup to mount the nfsroot, but forcing the use of nfs3 is useless.

Could someone help me figure out what I am doing wrong?

Thanks,

-- 
Nicolas