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 iostat
and iotop
are wonderful tools, they are rather limited in scope by comparison.
So, let us introduce dstat
. While 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.