The sys admin's daily grind: Nload
Talk About Graphs

© paradox, Fotolia
Network monitors are a dime a dozen, but Nload, which separates incoming and outgoing traffic and draws graphs on the console without X, is unique.
Displaying the network load on an interface is not difficult, and there are countless tools for visualizing the values. But which tool gives you the best graphical representation of the measured values? Hardliners would recommend grabbing the values from the /proc directory or would do something like
watch -n 10 "ifconfig eth0|grep bytes"
and work out the averages in their heads. Obviously, that would be showing off, and imagine the embarrassment if you miscalculate. Of course, you can rule out anything that requires X11 because servers don't typically have a graphical user interface. IPTraf will give you the figures you need, but it doesn't have a history feature. The same applies to Iftop [1], although it does tell you how much traffic is reaching or leaving each communications partner.
For a quick overview, my favorite tool is Nload [2]. Nload shows you the current network load for incoming and outgoing data, depending on the graph you select (Figure 1). At the same time, it gives you the average values for a configured interval. The history feature makes working with Nload a pleasure; there's no danger of missing a peak, even if you take your eyes off the screen for a moment. The -t <value> command-line parameter, with value in milliseconds, lets you set the update interval. By default, Nload will update its display twice a second. In most cases, a more relaxed setting is fine: I typically use -t 2000, an update every two seconds.

To keep the load graphs readable, you can set thresholds for incoming and outgoing traffic. If the data traffic exceeds the threshold value, Nload truncates the graph and then you know something is going wrong. The default threshold value is 10Mb/s, but you can modify this with the -i <value> parameter for incoming and the -o <value> parameter for outgoing traffic. The -s <value> parameter, with value between 1 and 9, lets you manipulate the average values. The smaller the number, the shorter the interval for which Nload calculates the averages. The highest value, 9, is the default. Another neat feature is the ability to modify critical parameters at run time – even the interface you are monitoring. Pressing O while Nload is running pops up an option menu. The changes are applied immediately.
The parameter -m is useful for servers with multiple interfaces; it tells Nload to display the load for multiple interfaces simultaneously, although you do lose the ability to draw histograms when you set this option.
Infos
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
News
-
KaOS 2022.06 Now Available With KDE Plasma 5.25
The newest iteration of KaOS Linux not only adds the latest KDE Plasma desktop but sets LibreOffice as the default.
-
Manjaro 21.3.0 Is Now Available
Manjaro “Ruah” has been released and includes the latest Calamares installer, GNOME 42, and much more.
-
SpiralLinux is a New Linux Distribution Focused on Simplicity
A new Linux distribution, from the creator of GeckoLinux, is a Debian-based operating system with a focus on simplicity and ease of use.
-
HP Dev One Linux Laptop is Now Available for Pre-Order
The System76/HP collaboration Dev One laptop, geared toward developers, is now available for pre-order.
-
NixOS 22.5 Is Now Available
The latest release of NixOS with a much-improved package manager and a user-friendly graphical installer.
-
System76 Teams up with HP to Create the Dev One Laptop
HP and System76 have come together to develop a new laptop, powered by Pop!_OS and aimed toward developers.
-
Titan Linux is a New KDE Linux Based on Debian Stable
Titan Linux is a new Debian-based Linux distribution that features the KDE Plasma desktop with a focus on usability and performance.
-
Danielle Foré Has an Update for elementary OS 7
Now that Ubuntu 22.04 has been released, the team behind elementary OS is preparing for the upcoming 7.0 release.
-
Linux New Media Launches Open Source JobHub
New job website focuses on connecting technical and non-technical professionals with organizations in open source.
-
Ubuntu Cinnamon 22.04 Now Available
Ubuntu Cinnamon 22.04 has been released with all the additions from upstream as well as other features and improvements.