Re-building nfsroot in multi-arch environment

[George {Skip} F VerDuin]

My recent work building nfsroot with good keys, has led me to find a new 
not understood behaviour -- fai-setup crosses into multiple architectures?

Background:  I have three nfsroots that are important to me: nfsroot, 
nfsroot-i386, nfsroot-amd64.  Faiserver is on an AMD-64 bladeserver host 
therefore today nfsroot & nfsroot-amd64 are probably extremely similar.  
My intention is to use the -i386 and -amd64 to support the hosts on my 
LAN, and experiment with the default nfsroot.  Actually I have a fourth, 
nfsroot-tango, that was built on another host and copied on to faiserver 
only for the purposes of comparison.  Please ignore the -tango but 
remember -- because it is a comparative base, I'd like for it to not be 
modified by any work in the future.

So to test keys and re-build my three nfsroots, I created a real simple 
script to drive the process using fai-setup.  The script creates fresh 
copies of the three install kernels and renames 
/var/log/fai/fai-setup.log to keep the logs for comparison.  Now when I 
"diff setup.log setup-amd64.log" I find the following excerpt:

1321,1323c1327
< Re-exporting directories for NFS kernel daemon...exportfs: Failed to 
stat /srv/fai/nfsroot-amd64: No such file or directory
< exportfs: Failed to stat /srv/fai/nfsroot-i386: No such file or directory
< .
---
 > Re-exporting directories for NFS kernel daemon....


When I look for the results of Re-exporting I find that 
.../nfsroot/boot/vmlinux... is duplicated from 
.../nfsroot-amd64/boot/vmlinux... (and the other files making up the 
install kernel).  I grepped /usr/lib/fai/ and /usr/sbin/ to find the 
source of the Re-exporting output line without finding it.

Now I'm curious to know the thinking behind Re-exporting to nfsroots 
other than the one being built at the moment.  It puts my -tango version 
at risk as a minimum (certainly not earth shattering).  But as I 
experiment with nfsroot, I really do not want to disturb any of the 
-i386, -amd64, or others, that are used for real work.  And if my eyes 
are not lying to me, is there a way to shut off the duplication?

One more thing:  When I use the -f parm on fai-setup (documented for 
fai-make-nfsroot) the process faults out with "Directory not empty." 
therefore my script includes a "rm -rf .../nfsroot..." that works just 
fine.  Have I violated fai-setup?

Cheers
Skip