System Administration

Essential System Tools: nmon – Curses based Performance Monitor

Last Updated on November 25, 2022

Summary

Nmon is an indispensable Swiss army knife type of utility. It does the work of at least six tools.

Its main strength is that with just a few keys you can have a single terminal displaying everything *you* want to monitor.

We’ve not described everything about nmon. Don’t forget its powerful capture mode (we’ll cover this in a future article). There’s also other real-time monitoring functionality that we’ve not included for space reasons such as NFS reporting.

Website: nmon.sourceforge.net
Support:
Developer: Nigel Griffiths
License: GNU General Public License v3 or any later version

nmon is written in C. Learn C with our recommended free books and free tutorials.

Pages in this article:
Page 1 – Introduction / Installation
Page 2 – In Operation
Page 3 – CPU Stats
Page 4 – Memory Stats
Page 5 – Disk Stats
Page 6 – Kernel Internal Stats
Page 7 – Virtual Memory Stats
Page 8 – Network Stats
Page 9 – Top-processes
Page 10 – Resources
Page 11 – Summary

Other tools in this series:

Essential System Tools
AlacrittyInnovative, hardware-accelerated terminal emulator
BleachBitSystem cleaning software. Quick and easy way to service your computer
bottomGraphical process/system monitor for the terminal
btop++Monitor usage and stats for CPU, memory, disks, network and processes
catfishVersatile file searching software
ClonezillaPartition and disk cloning software
CPU-XSystem profiler with both a GUI and text-based
CzkawkaFind duplicate files, big files, empty files, similar images, and much more
ddrescueData recovery tool, retrieving data from failing drives as safely as possible
dustMore intuitive version of du written in Rust
f3Detect and fix counterfeit flash storage
Fail2banBan hosts that cause multiple authentication errors
fdupesFind or delete duplicate files
FirejailRestrict the running environment of untrusted applications
GlancesCross-platform system monitoring tool written in Python
GPartedResize, copy, and move partitions without data
GreenWithEnvyNVIDIA graphics card utility
gtopSystem monitoring dashboard
gWakeOnLANTurn machines on through Wake On LAN
hyperfineCommand-line benchmarking tool
HyFetchSystem information tool written in Python
inxiCommand-line system information tool that's a time-saver for everyone
journalctlQuery and display messages from the journal
kmonManage Linux kernel modules with this text-based tool
KrusaderAdvanced, twin-panel (commander-style) file manager
NmapNetwork security tool that builds a "map" of the network
nmonSystems administrator, tuner, and benchmark tool
nnnPortable terminal file manager that's amazingly frugal
petSimple command-line snippet manager
PingnooGraphical representation for traceroute and ping output
ps_memAccurate reporting of software's memory consumption
SMCMulti-featured system monitor written in Python
TimeshiftReliable system restore tool
QDirStatQt-based directory statistics
QJournalctlGraphical User Interface for systemd’s journalctl
TLPMust-have tool for anyone running Linux on a notebook
UnisonConsole and graphical file synchronization software
VeraCryptStrong disk encryption software
VentoyCreate bootable USB drive for ISO, WIM, IMG, VHD(x), EFI files
WTFPersonal information dashboard for your terminal
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Mark Regan
Mark Regan
5 years ago

What terminal/window settings do I use in PuTTY when running nmon to get the correct line drawing?