Forgot to create a swap partition? Here’s how you add a swap file (do this with root privileges):

1. Create the actual file, we’ll go for 1GB (1048576 blocks à 1024 bytes = 1GB):

   dd if=/dev/zero of=/swapfile_1GB bs=1024 count=1048576

2. Set permissions:

   chmod 0600 /swapfile_1GB

3. Transform the file into a swap file:

   mkswap /swapfile_1GB

4. Activate the new swap file:

   swapon /swapfile_1GB

5. Make the swapfile permanent (surviving reboots):

   echo "/swapfile_1GB none swap sw 0 0" >> /etc/fstab