There is only one problem with these commands, most of them do not exist on CentOS 6 (per default), and must be installed, but not by using yum command.
I have given here only the tamer ones (that can be installed by yum).
Htop is a much advanced interactive and real time Linux process monitoring tool. This is much similar to Linux top command but it has some rich features like user friendly interface to manage process, shortcut keys, vertical and horizontal view of the processes and much more.
Installation (64-bit server) :
# wget http://packages.sw.be/rpmforge-release/rpmforge-release-0.5.2-2.el6.rf.x86_64.rpm
# rpm -ihv rpmforge-release*.rf.x86_64.rpm
# yum install htop
It is much more colorful than top ;-), and gives a better overview :
Iotop is also much similar to top command and Htop program, but it has accounting function to monitor and display real time Disk I/O and processes. This tool is much useful for finding the exact process and high used disk read/writes of the processes.
Necessary start conditions for installing this command : Kernel 2.6.18 i Python 2.4 with ctypes module
# yum install iotop
Option “-o” is best for usage, because it shows procvesses that are currently w/r on disc.
IoStat is simple tool that will collect and show system input and output storage device statistics.
This command is installed along with vmstat command, and they are both in a sysstat package :
# yum install sysstat
Here is the output :
Linux 2.6.32-358.14.1.el6.x86_64 (proxy-2013.moj.domen) 09/26/2013 _x86_64_ (4 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.11 0.00 0.03 0.01 0.00 99.86
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 0.92 2.22 31.19 2246760 31613266
dm-0 3.96 2.15 31.04 2182498 31459096
dm-1 0.02 0.04 0.11 38800 108800
dm-2 0.00 0.00 0.00 1362 80
IPTraf is an open source console-based real time network (IP LAN) monitoring utility for Linux.
It is in a previously installed repository, so installation is simple :
# yum install iptraf
Quite nice and useful view of traffic, with address grouping.
Good link for deciphering SAR command output.