How to create or add swap file on Linux and FreeBSD?

Sometime you need to increase swap memory to run softwares that need more swap as the requirement or to improve the system performance. In this article I will show you on how to add swap file to get more swap memory on Linux and FreeBSD. We will create 1 GB or 1024 MB swap size.

1. Adding swap file on Linux

Login as root or change to super user then type the following command to create 1 GB swap file.

dd if=/dev/zero of=/swap1 bs=1M count=1024

For example, my result is as below:

bash-3.1# dd if=/dev/zero of=/swap1 bs=1M count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 28.3646 s, 37.9 MB/s

Run ‘mkswap’ to set up a Linux swap area on a device or in a file, in this case in the /swap1 file.

mkswap /swap1

For example:

bash-3.1# mkswap /swap1
Setting up swapspace version 1, size = 1048572 KiB
no label, UUID=e501fc72-f731-4624-ab45-ee898f6cf1c5

After setting up the swap area, now we need to enable / activate the swap file by using ‘swapon’ command.

Read More: https://blog.oudel.com/how-to-create-or-add-swap-file-on-linux-and-freebsd/