Knowledgebase

preparation
Firstly, check if your system already has a Swap partition:
swapon -s
or
free -m
If no result is returned or the Swap column in free-m has a value of 0, it means that your system does not have a Swap partition.
Create SWAP partition
We can use the 'fall' command to create a 1GB Swap partition:
fallocate -l 1G /swapfile
If this command cannot be used, please install the utility Linux package:
apt install util-linux
Then set the permissions for this file:
chmod 600 /swapfile
Then activate the SWAP partition
mkswap /swapfile
swapon /swapfile
At this point, you can use the swap - s or free - m command to check if the Swap partition has been activated.
Set up auto start upon startup
We need to edit the file/etc/fstab and add the following content:
echo "/swapfile swap swap defaults 0 0" >> /etc/fstab
Great job done, use the free - m command to check if the Swap partition is correct:
Adjust the Swappiness value of the system kernel
Swapiness is a property of the Linux kernel that defines the frequency at which the system uses swap space. The value of Swapiness ranges from 0 to 100 (default is 60), with a low value causing the kernel to avoid swapping as much as possible, and a high value causing the kernel to use swap space more actively.
This value defaults to 60, and we can use the cat/doc/sys/vm/swappiness command to check the current value.
Usually we can change it to 10:
echo "vm.swappiness=10" >> /etc/sysctl.conf
Then use the sysctl - p command to make it effective.
Close Swap
Sometimes we need to close the Swap partition, you can use the following command:
Firstly, disable the Swap partition:
swapoff -v /swapfile
Then check/etc/fstab and delete the/swap file swap swap defaults 0 0 line.
Finally, delete the file/swap file:
rm /swapfile