Creating A File Based Swap Partition
Written by: Will Kruss on 05 April 2019 01:48 PM
Need a swap partition on your VPS? you should use a file based swap partition. Learn the simple steps & do it yourself
Use a file as a swap partition
If you require a swap partition on your VPS, it's recommended to use a file based swap partition. To add one follow the below instructions.
The following dd command example creates a swap file with the name “myswapfile” under /root directory with a size of 1024MB (1GB).
# fallocate -l 2G /root/myswapfile # ls -l /root/myswapfile -rw-r--r-- 1 root root 1073741824 Aug 14 23:47 /root/myswapfile
Change the permission of the swap file so that only root can access it.
# chmod 600 /root/myswapfile
Make this file as a swap file using mkswap command.
# mkswap /root/myswapfile Setting up swapspace version 1, size = 1073737 kB
Enable the newly created swapfile.
# swapon /root/myswapfile
To make this swap file available as a swap area even after the reboot, add the following line to the /etc/fstab file.
# pico /etc/fstab /root/myswapfile swap swap defaults 0 0
Verify whether the newly created swap area is available for your use.
# swapon -s Filename Type Size Used Priority /dev/sda2 partition 4192956 0 -1 /root/myswapfile file 1048568 0 -2 # free -k total used free shared buffers cached Mem: 3082356 3022364 59992 0 52056 2646472 -/+ buffers/cache: 323836 2758520 Swap: 5241524 0 5241524
Note: In the output of swapon -s command, the Type column will say “file” if the swap space is created from a swap file.
If you don’t want to reboot to verify whether the system takes all the swap space mentioned in the /etc/fstab, you can do the following, which will disable and enable all the swap partition mentioned in the /etc/fstab
# swapoff -a # swapon -a
Single Cut/Paste version
dd if=/dev/zero of=/root/myswapfile bs=1M count=1024
chmod 600 /root/myswapfile
/root/myswapfile swap swap defaults 0 0