This article was originally posted in February, 2011 and may be out of date. You may also wish to read Link: How to Install and Setup Monit (Linux Process and Services Monitoring) Program.
Here’s an article that will be helpful to may of you who are running PBX servers under CentOS, especially (but not limited to) those running on virtual machines with low disk storage space. Note that if you installed from an “all-in-one” distribution ISO, this possibly might already be installed, but may still need to be configured.
One thing you definitely don’t want to happen to your server is for it to run out of disk space, especially the root partition.
There are lots of pieces of open source monitoring software, a popular one being monit.
Below is a quick guide to installing monit and generating alert e-mails for disk space and cpu/memory usage. The installation was done on a SysAdminMan VPS running CentOS 5.5
Full article here (SysAdminMan)
The instructions should work for any system running CentOS 5.5. You might be tempted to take a shortcut and just do “yum install monit” but please be aware that (at least as of the day I’m writing this) it will get you a much older version of the software, so I suggest you stick with the instructions in the article. I have just now installed this on one system and have not fully tested it, but it did send an e-mail confirming that it had started.
This is just another tool you can use to make your life a little easier and help you avoid a problem before it becomes a major headache!