One of the utilities contained in sysstat is pidstat, which can measure the average CPU usage of Linux processes. For this purpose, a Linux tool set called sysstat may come in handy, which contains a collection of performance monitoring tools for Linux, reporting statistics on disk I/O, CPU, memory, networking, and other system activities. As the CPU usage of a process can fluctuate over its lifetime, you will want to measure the average CPU usage or CPU utilization of the process.

Sometimes you may want to know the CPU usage of a particular Linux process. The advice given by VMWare about this is 'Don't trust metrics measured from within the VM'.How to measure the average CPU utilization of a Linux process I have seen a single process showing up as using 9999% CPU in top from within a VM. This is a very good indicator of how slow your system will feel to use.Īnother note on CPU utilisation, virtual machines can dynamically alter the CPU capacity in response to the needs of the VM. This is an indication of how many processes are currently waiting to get on a processor. The other key metric to watch is the 'load average'. Bear in mind that 25 Apache processes using 10% CPU each shows up differently in top to a single MySQL process using 250% CPU. For that, top or htop at the time is your best bet. Generally, these will not tell you which process was using all the CPU at any given time.

Once you install one of them, you will have trouble remembering how you lived without it. (Although Nagios can do graphing, this is not its forte.) There are plenty of questions on ServerFault already about which monitoring system is the best.

The simplest way to access them is to type sar on the command line.Ī far better option is to install a monitoring system such as Cacti, Munin or Zabbix. The sar utility collects some statistics about your system if it is switched on.

Linux see cpu usage