Anticipating problems and resource shortages on a slice can be more valuable than fixing them after they've happened. A monitoring tool like munin lets you watch your slice's resource use over time. The graphs will highlight issues before they cause downtime or bandwidth quota overages.
There are a number of monitoring tools out there, and each have their own strengths. Munin's focus is providing graphs over time showing system statistics like memory use, disk space, and network activity. Munin can also monitor several slices from a single master server. The setup is more complex than using a commercial monitoring service, but the benefit is that you have more control over what is monitored and how the information is presented. Well, and it's free. There's that too.
The first article in the series covers the installation of munin and some configuration options.
- * What you'll need
- * Installing packages
- * The munin.conf file
- * Email notification
- * The host tree
- * The munin-node.conf file
- * The munin-node service
Later articles cover further configuration, testing the installation, and adding more servers to be monitored.
What you'll need
Munin's output is in html, so you will want to have a web server running to make reports available through a web browser. You can use any web server, such as apache or nginx, but for convenience the examples in this article series will assume you are running apache. It's best if you go through a tutorial series for installing apache or nginx so you understand what's being installed, but there are also barebones instructions for a default apache install in our repository if you're an experienced user and just want the web server for the purposes of accessing munin's reports.
If you want munin to send you email alerts you'll need to have a mail server running on your munin master slice that is configured to send outgoing mail messages. Slicehost has several articles that go into detail on setting up a mail server, and as with the web server, it's best if you go through a tutorial series so you get a good explanation of how to set up the mail server. If you want a quick, minimal mail server install, however, there are barebones install articles available there as well.
Munin can monitor just a single slice or it can be used to monitor several slices from one "master" slice. If you are planning on monitoring additional slices later, be sure to perform this installation on the slice you want to use as munin's master. If you are monitoring only one slice you don't have to make that decision, of course — just follow the directions in this series and don't worry about the subsequent article on installing additional nodes.
All commands assume you're running as a non-root user with sudo access.
To access the initial munin install article that corresponds to the Linux distribution running on your slice, click the appropriate link below:
Ubuntu: Installing munin on Ubuntu
Debian: Installing munin on Debian
CentOS: Installing munin on CentOS
Fedora: Installing munin on Fedora
Red Hat Enterprise Linux: Installing munin on RHEL
For more information about running Munin, including their FAQ and documentation, visit the Munin Project's web site.
- -- Jered