Eventually, we will want to view multiple types of system activity simultaneously. While
sar has many operating modes, its output is linear. Without a tool to interpret its exhaustive data, we are left with a lot of manual analysis of several
sar invocations. While
iotop are wonderful tools, they are rather limited in scope by comparison.
So, let us introduce
dstat can't access historical data like
sar, it can display output from several different operation modes side by side. It also includes color coding to easily distinguish units. It's a very pretty command-line tool and it summarizes several different metrics at a glance.
For servers that are of particular importance, we actually keep a terminal window that displays the
dstat results open so that we get an early warning when numbers begin to look bad.