create swap space in ec2 instace

TO create swap space 

sudo /bin/dd if=/dev/zero of=/var/swap.1 bs=1M count=2048 # count is swap space in mb 2048 mean 2GB ram
sudo /sbin/mkswap /var/swap.1
sudo chmod 600 /var/swap.1
sudo /sbin/swapon /var/swap.1

To make them as permanent in serer or in system add into the /etc/fstab

/var/swap.1   swap    swap    defaults        0   0


note:
if ram < 2GB ram:
  swap_space = ram*2
elif ram > 2GB ram:
  swap_space = ram+2