replace_dir() { #SAVE_LAYER=/pup_rw #Line 690 of initrd/init
 #setup empty /tmp on tmpfs for in stack
 rm -rf ${SAVE_LAYER}/tmp
 #adjust stack
 echo "mount -o remount,prepend:${SAVE_LAYER}=rw,mod:/mnt/tmpfs/pup_rw=ro,del:/mnt/tmpfs/pup_rw /pup_new" #debug
 mount -o remount,prepend:${SAVE_LAYER}=rw,mod:/mnt/tmpfs/pup_rw=ro,del:/mnt/tmpfs/pup_rw /pup_new
 if [ $? -eq 0 ];then
  rm -rf /mnt/tmpfs/pup_rw
  KEEPMOUNTED="${KEEPMOUNTED}${SAVEPART} "
  [ "$SAVE_NAME" ] && NEWUNIONRECORD="$SAVE_NAME $NEWUNIONRECORD"
 else
  printf "${L_ADDING_SAVE_LAYER_FAILED}\n" "$SAVE_LAYER"
 fi
}