Unix command to find CPU Utilization

Q. I am using Solaris UNIX. How do I find out CPU Utilization under Sun Solaris UNIX?

A. Under Sun Solaris UNIX (and other UNIX oses like HP-UX and *BSD oses) you can use following commands to gather CPU information:

=> sar : System activity reporter

=> mpstat : Report per-processor or per-processor-set statistics

=> ps / top commands

Note: Linux specific CPU utilization information is here. Following information applies to UNIX only.

UNIX sar command examples

General syntax is as follows:
sar t [n]
In the first instance, sar samples cumulative activity counters in the operating system at n intervals of t seconds, where t should be 5 or greater. If t is specified with more than one option, all headers are printed together and the output may be difficult to read.

Task: Display today’s CPU activity, use

# sar

Task:Watching system activity evolve i.e. reports CPU Utilization

# sar -u 12 5

Where,

  • -u 12 5: Comparison of CPU utilization; 12 seconds apart; 5 times.

Output includes:

  1. %usr: User time (% of CPU)
  2. %sys: System time (% of CPU)
  3. %wio: Percent of CPU running idle with a process waiting for block I/O
  4. %idle: Percent of CPU that is idle

Task: You can watch CPU activity evolve for 10 minutes and save data

# sar -o file-name 60 10

Task: You can just sar and logout and let the report store in files

# nohup sar -A -o output-file 60 10 1>/dev/null 2>&1 &
Note to display data stored in output-file pass -f option to sar command:
# sar -f output-file

UNIX mpstat example

Type the following command to display per-processor statistics; 12 seconds apart; 5 times
# mpstat 12 5

You can also use traditional ps and top command:
# top
# ps -e -o pcpu -o pid -o user -o args

Read man pages of ps, top, mpstat and sar for more information.

Posted by: SXI ADMIN

The author is the creator of SXI LLC and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.