System monitoring

Use smartmontools (S.M.A.R.T. monitoring tools) on Debian-based operating system to perform disk check.

Monitor multiple log files at once using MultiTail utility.

Use system performance tools for Linux to display process statistics.

Use Filebeat to deal with many small log files.

Protect Netdata using basic access authentication.

Install netdata on Debian Buster to perform real-time performance monitoring.

Convert outdated system activity information binary datafile to current format, so it could be read by up-to-date application.

You already know how to collect and report system activity information, so it is the best time to learn how to export already collected data.

Use netstat, ss or files inside proc filesystem to count TCP connections.

Collect and report system activity information using sysstat a system performance tools for the Linux operating system.

Install and configure Dashing with Icinga 2 to use the external board for your Icinga2 instance.

Upgrade icinga2 and its web-interface using official/dedicated repository and PostgreSQL database.

Create custom data field to define multiple domain names and service apply rule to verify those SSL certificates.

Icinga2 documentation clearly describes the master->satellite->client setup, but as of now everything can be configured using the director module and a top down approach, so you can easily monitor external remote networks that are not accessible from the master server.

The free utility is used to display the amount of free and used memory in the system. Debian Stretch provides an upgraded package. The output format has changed, and available memory is calculated using a different method, so let’s see what we can do with these modifications at this moment.

Add your first host using icinga2 director after performing clean installation as I have described earlier this month – icinga2 plus icingaweb2 and director module installation procedure.

Icinga is a great monitoring solution, especially when you use the director module to perform configuration in a top down environment. It makes the application more accessible to more people as you can use the web-interface and role-based permissions to allow developers and testers to write and use their own checks and notifications.

Install Icinga 2 monitoring instance with web-interface.

If you have ever wondered how to perform real-time performance monitoring on a number of virtual hosts scattered across multiple locations, then install and use netdata application.

I have described a simple way to configure the AWStats web-interface last month, so I will continue this topic further and tell you how to add a menu to quickly switch between configured sites.

I will show you how to configure the AWStats web-interface using the uWSGI application server and Nginx HTTP server, which is a very simple and straightforward process.

It is an interesting thing to know how to parse and process Linux Software RAID events. It is also beneficial as you can automatically take appropriate action immediately after a certain event occurs.

Recently described hddtemp application does not contain every possible hard drive in its database. I’ll be honest here, its development stopped many years ago, but it is still very useful, so I will shortly describe how to add new hard drive to the database.

It is often overlooked that hard drives which are available on the market provide temperature measurements. This temperature can be effortlessly monitored using hddtemp application by Emmanuel Varagnat.

A long time ago, I wrote several blog posts which related to Ubiquiti devices, especially monitoring using Cacti rrdtool-based graphing solution. These are probably obsolete now, but someone has pursued this idea further…

Recently, I was searching for an easy to manage VNC service to use it at home. After a short while of consideration, I decided to install TigerVNC and manage it using Monit.

A short time after I installed Monit, I tried to monitor a background running process that does not support daemon mode. It is an exceptionally rare situation, but very interesting one, so after a while I came up with a quite simple solution using additional shell script.

Previous entry was too long to include additional screenshots of the web-interface, so today I will write a couple of words about web-interface and show you several screenshots.

I have been using self hosted Kolab Groupware everyday for quite a while now. Therefore the need arose to monitor process activity and system resources using Monit utility.

Today, I will show you how to create a simple shell script to read and print interface statistics on the Cisco Catalyst switch using the SNMP protocol.

By default, the dmesg command prints the kernel ring buffer with a timestamp for each logged message. It is easy to change this behavior and display date/time in a human-readable form using just one additional parameter. Still, sometimes it is not supported, so I will shortly touch upon this topic.

Last year I published the blog post Cacti – How to graph CCQ on Ubiquiti devices. Recently I updated ubiquiti_ccq.pl script, so it will work with all NanoBridge and PowerBridge devices.

Recently battery in my notebook started to behave erratically. It will charge only to 70-80% of its maximum capacity. I suspect that it is probably slowly dying, so I will have to replace it soon, but at first, I will look at several utilities to monitor battery capacity.

As you probably already know, the CCQ value is not available via SNMP (AirOS 5.5.2), but of course it doesn’t mean it can’t be graphed using Cacti. To graph CCQ on Ubiquiti devices, you just need to use a simple script to read the desired value using the web interface.

To change the data source name, you need to check its current value and then issue a single rrdtool command.

Signal strength on Mikrotik devices can be monitored by Cacti using SNMP protocol. It is straightforward if you have just a couple of those devices but you can be easily overwhelmed by dozens of data templates because the wireless card’s MAC address is part of the OID.

Just two simple steps – create logging action and rule.

Install lm-sensors package: $ sudo apt-get install lm-sensors Execute sensors-detect command as root: $ sudo sensors-detect It will determine needed modules and at the end it will ask for your permission to automatically add them to the /etc/modprobe file. If you answered yes then load them using command: $ sudo service module-init-tools start Now you can use sensors command: $ sensors acpitz-virtual-0 Adapter: Virtual device temp1: +44.0°C (crit = +100.0°C) temp2: +44.0°C (crit = +100.0°C) coretemp-isa-0000 Adapter: ISA adapter Physical id 0: +45.0°C (high = +86.0°C, crit = +100.0°C) Core 0: +45.0°C (high = +86.0°C, crit = +100.0°C) Core 1: +44.0°C (high = +86.0°C, crit = +100.0°C)

Store and stop processing specific log.

It’s easy to miss something when you need to monitor a dozen logs on different servers and some other devices. Fortunately, there is a simple solution as you can use rsyslog with PostgreSQL or MySQL support to store all local and remote events on your network and then visualize results using LogAnalyzer.