Strange SATA Disk Performance

Below is a GNUPlot graph of ZCAV output from a 250G SATA disk. The disk has something wrong with it (other disks of the same brand in machines of the same configuration give more regular graphs). The expected graph will start high on the Y scale (MB/s) and steadily drop as the reads go to […]

Advertising Free Software Projects

Today I just noticed the following advert on one of my web pages: MINIX3 is a new reliable free operating system. Smaller than Linux. Try it It’s free!

This made me think about some of the potential ways of advertising free software projects. It seems that in some ways Google Adwords is not the […]

Xen and Heartbeat

Xen (a system for running multiple virtual Linux machines) and has some obvious benefits for testing Heartbeat (the clustering system) – the cheapest new machine that is on sale in Australia can be used to simulate a four node cluster. I’m not sure whether there is any production use for a cluster running under Xen […]

Who Benefits when Cheap Electricity is used?

In a comment on my previous blog post a question was asked as to who benefits when customers are able to use cheap electricity.

The answer is that the electricity company benefits the most! When electricity sources such as wind and solar power which can vary in capacity are used the electricity would be cheaper […]

Backup for Wind Power

A question that people often ask about wind power (and was asked in the comments section of my previous post) is what can be done when the wind speed decreases in an area. There are several methods that can be used to address this problem.

The easiest option is to simply have wind farms spread […]

Pointers in Bash Shell Scripts

# foo=bar # name=foo # echo ${!name} bar

The above example shows how to make a bash environment variable reference the value of another.

# echo ${!f*} foo fs_abc_opts fs_name

The above example shows how to get a list of all variables beginning with “f” (NB the wildcard can only go at the end).

Related posts:

Heartbeat service scripts A service script for Heartbeat needs to support at least…
configuring a Heartbeat service In my last post about Heartbeat I gave an example…
Xephyr As part of my work on Xen I’ve been playing…

A Lack of Understanding of Nuclear Issues

Ben Fowler writes about the issues related to nuclear power in Australia. He spends 8 paragraphs discussing the issues on the “Right” side of politics – of which 6 concern the an Australian nuclear weapons capability and then spends 3 out of 5 paragraphs related to the “Left” side explaining that he thinks that everyone […]

Rackspace RHEL4 updates

A default RHEL4 install of a Rackspace (*) server contains a cron.d file named /etc/cron.d/rs_rhncheck that runs a job to check for Red Hat Network updates. In the default configuration this would send out a message every day indicating that up2date did nothing. To only get email when there is something interesting happening I changed […]

Nixforce unauthorised use

Just over two days ago I sent a DMCA take-down request to for copying my content in violation of the non-commercial license that I offer, I have not had a response from them and they have kept mirroring my site.

I have just sent a DMCA take-down to which appears to be their […]

Easy Search Engine Optimisation in WordPress

The first thing you need is to have meta keywords in the pages. The solution I discovered for doing this is the All In One SEO Pack, this automatically makes the categories of a blog post become meta keywords, allows adding arbitrary meta keywords when editing the blog post, and supports keywords for the entire […]