Add swap file in linux on debian

in Command Line, Linux

How to add a swap file to an existing file system is almost trivial.

First decide how big you want it. I choose 1GB w/ a 1GB RAM machine.

Second create the file. 

dd if=/dev/zero of=/swapfile bs=1024 count=1048576

Next make it a swap. 

mkswap /swapfile

Add it as a swap. 

swapon /swapfile

Edit fstab. 

vim /etc/fstab

Add

/swapfile none swap sw 0 0

Save and verify output 

/swapfile none swap sw 0 0