How to create a swap partition in Linux

1. Run the following command to create a file of 1 GB, for example:

# dd if=/dev/zero of=/swapfile bs=1M count=1000 

2. Run the following command to modify the file permissions :

 # chmod 600 /swapfile 

3.Run the following command to configure the file as swap space:

 # mkswap /swapfile 

4.Run the following command to activate the swap file:

 # swapon /swapfile 

5. To mount the swap partition automatically upon system startup, add an entry for the swap file to /etc/fstab.

 # echo "/swapfile swap swap defaults 0 0" >>/etc/fstab 

6. Run the following command to mount the swap partition:

 # mount -a