Greetings, It has been a while since we posted any useful tidbits for you , so we have decided to share one of our quick & dirty centralized backup scripts. The script relies on ssh key based authentication, described here on this blog. It essentially parses a configuration file where each variable is separated by […]

I decided to write this little guide to provide the relatively simple steps needed to migrate your linux system to a Xen (HVM) virtual instance. It is assumed that on your source and destination boxes, that you only have one root “/” partition. If you partitioned out your file system differently, you will have to […]

One way to increase the efficiencies of Xen based systems is to utilize templates. VMware talks about this in their whitepaper for ESX2 best practices. With Xen, you have to create your own. Here is a straight forward guide for how to do it. 1. Bootstrap a DomU named -tpl (e.g. centos4-tpl). I recommend using […]

In yet another post in our automation series, we will share a bash script that automates the deployment of debian based load balancers (specifically with LVS / Linux Virtual Server project). Even though the environments and systems you deploy may start to get more complicated such as with load balancers, there will always be a […]

Automation is as necessary as any other aspect of systems administration in any critical or production environment where growth and scalability are moving at a significant pace. Growth in any organization is obviously a good thing. In the systems administrator’s perspective, however, growth can mean more time spent deploying systems and less time spent focusing […]

Sometimes its necessary to relay your mail through a third party provider. If your server environment has a dedicated sendmail server (most do), then this scenario is applicable to you. It is ideal to centralize your outgoing mail to one server so that changes, policies and configuration is located in a single place. In this […]

A custom iptables script is sometimes necessary to work around the limitations of the Red Hat Enterprise Linux firewall configuration tool.

With all the patch management solutions, local repositories and other options, it is rarely necessary to manually scan all servers on your network to build a “report” of the patch levels in your environment. Sometimes it is, however. For instance, if you are brought into an environment that has not been properly managed and require […]

The idea behind this script is to have a centralized, highly secure and restricted key repository server. Each server in your environment would run this script to “pull” the updated key list from the central server. The script would run as a cron job and can run as often as you like. Ideally every 5-10 minutes would allow for quick key updates / distribution.

I decided to post this article on implementing a simple single mail server with anti-spam and anti-virus capabilities.

This guide hopefully will help you on your way to configuring a basic mail system on Linux (specifically Debian).