mkswapfile1G.sh

#!/bin/bash

swapfile='/var/swap'
backupfile="$swapfile-`/bin/date +%Y%m%d-%H%M%S-$$`"
blocksize='1G'
count='1024'

if [ $UID -ne "0" ] ; then
  echo "please re-run as root via sudo."
  exit 1
fi

if [ -e $swapfile ]
then
  echo "File exist( $swapfile )."
  exit 1
fi

echo "creating a swap file."
echo "Please wait requires some time..."
umask 077
dd if=/dev/zero of=$swapfile bs=1M count=1024

echo "mkswap"
mkswap -c /var/swap

echo "backup $swapfile $backupfile"
cp -p $swapfile $backupfile
echo "$swapfile	swap	swap	0	0" >> /etc/fstab


echo "swapon"
swapon -a
swapon -s
echo "Done."
exit