The first half of this year (is it really already May?) was quite swamped and i did not came about writing any new blog entry. I also outsmarted myself, in  a way, by always wanting to write complete, reads large, reviews / articles. As a matter of fact, i began to write a couple – [...]

Not everything fitted in the first article and i felt a too long “first steps” article might alienate beginners. This time, i will go into some more advanced matters such as: stickiness vs location, N+1 clusters, advanced resource locations, clones and master/slave situations. Before reading this article, you should at least get your feed wed [...]

With squeeze around the corner it’s time to reconsider your everything with debian – once again Of course i am aware, that pacemaker is available since 2008, but sticking to debian stable, my first contact with pacemaker came with squeeze. Also, i was not really aware what i missed, because my simple setup just worked. [...]

This article is about puppet or puppetmaster, a newish tool for “data center automation and configuration management”. If you have to administrate more then one server, you probably end up repeating the same tasks over and over again on multiple machines, deploying the same configurations (maybe with minor changes) to your systems and spend and [...]

One of our mail servers has recently reached the lastly set max IMAP connection limits and i had to increase the login_max_processes_count value again (see here). However, upon restart i go this error: IMAP/POP3 mail server: dovecotWarning: fd limit 1024 is lower than what Dovecot can use under full load (more than 1512). Either grow [...]

Recently, i stumbled across this great new document store database called MongoDB. It is really easy to setup and maintain in Debian and i use it in a recent project of mine. However, after having hear me praising this great DB, an office colleague, who is also hosted at our company liked to play with [...]

I am developing a new mail server anti spam solution called decency.  It is a one-in-all solution attempt implementing a policy server (postfix policies), a content filter and a log parser. All three of them run in separate servers but are designed to communicate with each other to improve the spam detection rate a lot. [...]

Yet another blog about setting up LXC (Linux Containers). The article is focused on the current testing of debian called squeeze. (Cause some day it gotta be released!) Setup network with bridging. Network setup. Install LXC. Create your very first Container. Usage of container templates. Limiting ressources for containers (including: get the memory controller working)

This article is about a strange network problem occuring when used bridging in a XEN environment. Symptoms Some DomU is not reachable from the network anymore. The problem persists after restarting the DomU (all: reboot, shutdown+create, destroy+create). Possible: The DomU still has a virtual NIC, if pings are send from DomU via console only arp-requests [...]

This article is about setting up Endian 2.3 on a XEN machine without hardware virtualization (hvm). We work in a shared office space. It’s none of those big anonymous spaces where you can rent in on a monthly basis, but it does not belong to us alone. We share it with p4930 (architects) and control-b [...]