To check the swap usage size and utilization in Linux, you can use the free command with the -h option to display the output in human-readable format.
free -h
The output will show the total amount of swap memory, used swap memory, and free swap memory, as well as other information about the system’s memory usage. Here’s an example of the output:
total used free shared buff/cache available
Mem: 7.7G 3.0G 1.2G 138M 3.5G 4.3G
Swap: 2.0G 456M 1.5G
In this example, the total swap memory is 2.0 GB, and 456 MB of it is currently being used. (https://rpdrlatino.com)