dd if=/dev/zero of=/var/swapfile bs=1M count=4096
chmod 0600 /var/swapfile
/sbin/mkswap /var/swapfile
/sbin/swapon /var/swapfile
echo "/var/swapfile swap swap defaults 0 0" >>/etc/fstab
/sbin/swapon -s

cat /proc/meminfo

free -m