UNIX for Dummies Questions & Answers

Hi all,

Is it possible to get total memory usage and free memory usage without top? By Googling I found for total memory usage, use vmstat, for CPU, use mpstat, for disk I/O use iostat, is this correct? Will using sar gives the same result as ALL of these three (3) commands?

What about if I want to get CPU and memory usage information for a particular process, use ps?

Any advise will be much appreciated. Thanks in advance.

For a given process it varies by OS. If you have a /proc filesystem then those are used, for example in Solaris - pfiles, ptime - etc to get a per process look at things.

vmstat, iostat, and possibly sar are all standard choices, pick any or all of them.
The problem comes down to: learning to read and interpret the output of them. If you stick with sar, expect to read a lot of documentation

On Linux, you can better use

Code:

ps -eo pid,comm, nice, ppid,pcpu,pmem,vsz,args,user,tty | sort +4n | tail -1