What commands are used to retrieve CPU, memory, and disk usage percentages?

To retrieve CPU, memory, and disk usage percentages in a Linux environment, you can use the following commands:

1. CPU Usage

You can use the top command or mpstat from the sysstat package.

• Using top:

  top -b -n 1 | grep "Cpu(s)"

  This command runs top in batch mode for one iteration and filters the output to show CPU usage.

• Using mpstat:

  mpstat 1 1

  This command shows CPU usage statistics, where 1 1 means to report every second for one iteration.

2. Memory Usage

You can use the free command.

free -m

This command displays memory usage in megabytes. The output includes total, used, free, shared, buffer/cache, and available memory.

3. Disk Usage

You can use the df command.

df -h

This command shows disk space usage in a human-readable format. It lists all mounted filesystems along with their usage percentages.

Example Output

• CPU: The output from top might look like:

  %Cpu(s):  5.0 us,  2.0 sy,  0.0 ni, 93.0 id

• Memory: The output from free might look like:

               total        used        free      shared  buff/cache   available
  Mem:           7976        1234        4567         123        3210        6789

• Disk: The output from df might look like:

  Filesystem      Size  Used Avail Use% Mounted on
  /dev/sda1       100G   30G   65G  32% /

These commands provide a quick overview of system resource usage. Let me know if you need further details or examples!