This is an example of how I start to create a new stateless image

mk_statelss_xcat_node.sh

#!/bin/sh
#  CREATE XCAT STATLESS IMAGE
#    -- note you can not make a statless image for a distro other than the one this script is running on
#  -- That is various tools will fail if you try to build fedora on centos, or centos6.1 on centos6.4
#
#  Setup DISTRO Variables
DIST=`lsb_release  -i | cut -d: -f2 | sed 's/\s//g' `
REL=`lsb_release  -r  | cut -d: -f2 | sed 's/\s//g' `
MAJ=`echo $REL        | cut -d. -f1 | sed 's/\s//g' `
release=rh$MAJ
ARCH=` uname -m`
DISTRO=$DIST$REL
DISTRO_LC=`echo $DIST$REL | tr '[A-Z]' '[a-z]'`
ISO_DISTRO=$DIST-$REL
ISO_ARCH=$ARCH
DISTRO_VERS=$REL
HEADNODE_NAME=xcat
DOMAIN=cluster.example.com
NODE_TYPE=baseimage
INST_ROOT="/install/netboot/${DISTRO_LC}/${ARCH}/${NODE_TYPE}/rootimg" 

# Run genimage to make chrooted OS in $INST_ROOT
cd /install/custom/netboot/centos/
./genimage -i eth0 -n tg3,bnx2 -o ${DISTRO_LC}  -p ${NODE_TYPE} 


#  do some majik here
#  add any customization you want on the image here
#  example
#     install -m 600   /root/file  $INST_ROOT/root/file
#

#  Create the initrd image
packimage -p  ${NODE_TYPE} -a ${ARCH}  -o ${DISTRO_LC}

#  Configure node to boot from this statless image
nodeset nodename osimage=${DISTRO_LC}-${ARCH}-netboot-${NODE_TYPE}