How to monitor server using command line

This tip full of commands is mainly for Linux admins, but you may find utility sar very useful also in Solaris environment. They will help you find a bottleneck of your system, so read on..

First be sure to install sysstat package (exists almost in every Linux - Slackware, CentOS, Debian,..).

To monitor CPUs usage use commands:

mpstat -P ALL 1
sar -q -u
sar -q -u 1 0
top

IO activity on devices:

iostat 1
sar -d        #good stuff
sar -d 1 0
vmstat -d 1

Memory activity:

vmstat 1
sar -r 1 0

Network activity:

netstat -in -c
sar -n DEV 1 0

Some load+mem statistic:

sar -q -r
sar -q -r 1 0