How to create a swap storage on existing file system.

RedHat OS uses swap as a type of “Virtual Memory “in case your physical memory begins to run low. This capacity can be helpful for the system that don’t have enough physical memory ( RAM ).
You can define swap on your existing file system wherever you got free space instead of arranging a separate partition.

Follow the steps to achieve these settings.

Steps-1

Check the free space available on your existing storage.

Output

I have 4.8G available on my root ‘/’.

Step-2
Create swap on ‘/’ (root)

We will create 1G file using ‘dd’ command to create an output file size which is desirable.

Output:

Note: “count” calculations based on 1024×1024
It will create a 1 GB file on root partition.

Step-3

Now we have ‘/swap1Gfile’ swap on root it’s time to overlay swap file system on it.
let’s do it .

Output :

Step-4

Using ‘swapon’ we will Active swap to perform as an additional virtual memory in case system kernel is in panic situation just cause of shortage of RAM.

Output :

Step-5
Verify it’s loaded or not

Output :

Step-6
 

For making this changes permanent lets add this swap file as a swap storage into the ‘/etc/fstab’ file to survive on reboot.

Add the below line in your ‘/etc’fstab’ file.

Step-7
Once off swap partitions in order to read ‘/etc/fstab’ changes.

Use this below command to read swap partitions from ‘/etc/fstab’ file.

Verify it works or not

Output :

Let me know if you have any questions below in Comments Section .