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Ethernet Interface Naming With Systemd

Systemd has a new way of specifying names for Ethernet interfaces as documented in systemd.link(5). The Debian package should keep working with the old 70-persistent-net.rules file, but I had a problem with this that forced me to learn about systemd.link(5).

Below is a little shell script I wrote to convert a basic 70-persistent-net.rules (that only […]

Unikernels

At LCA I attended a talk about Unikernels. Here are the reasons why I think that they are a bad idea:

Single Address Space

According to the Unikernel Wikipedia page [1] a significant criteria for a Unikernel system is that it has a single address space. This gives performance benefits as there is no need […]

Compatibility and a Linux Community Server

Compatibility/interoperability is a good thing. It’s generally good for systems on the Internet to be capable of communicating with as many systems as possible. Unfortunately it’s not always possible as new features sometimes break compatibility with older systems. Sometimes you have systems that are simply broken, for example all the systems with firewalls that block […]

Using LetsEncrypt

Lets Encrypt is a new service to provide free SSL keys [1]. I’ve just set it up on a few servers that I run.

Issues

The first thing to note is that the client is designed to manage your keys and treat all keys on a server equally with a single certificate. It shouldn’t be […]

Finding Storage Performance Problems

Here are some basic things to do when debugging storage performance problems on Linux. It’s deliberately not an advanced guide, I might write about more advanced things in a later post.

Disk Errors

When a hard drive is failing it often has to read sectors several times to get the right data, this can dramatically […]

Sociological Images 2015

The above sign was at the Melbourne Docks in December 2014 when I was returning from a cruise. I have no idea why there are 3 men and 1 woman on the sign (and a dock worker was also surprised when I explained why I was photographing it). I wonder whether a sign that […]

LUV Server Upgrade to Jessie

On Sunday night I started the process of upgrading the LUV server to Debian/Jessie from Debian/Wheezy. My initial plan was to just upgrade Apache first but dependencies required upgrading systemd too.

One problem I’ve encountered in the past is that the Wheezy version of systemd will often hang on an upgrade to a newer version. […]

Mail Server Training

Today I ran a hands-on training session on configuring a MTA with Postfix and Dovecot for LUV. I gave each student a virtual machine running Debian/Jessie with full Internet access and instructions on how to configure it as a basic mail server. Here is a slightly modified set of instructions that anyone can do on […]

Running a Shell in a Daemon Domain

allow unconfined_t logrotate_t:process transition; allow logrotate_t { shell_exec_t bin_t }:file entrypoint; allow logrotate_t unconfined_t:fd use; allow logrotate_t unconfined_t:process sigchld;

I recently had a problem with SE Linux policy related to logrotate. To test it out I decided to run a shell in the domain logrotate_t to interactively perform some of the operations that logrotate performs […]

A Long Term Review of Android Devices

Xperia X10

My first Android device was The Sony Ericsson Xperia X10i [1]. One of the reasons I chose it was for the large 4″ screen, nowadays the desirable phones (the ones that are marketed as premium products) are all bigger than that (the Galaxy S6 is 5.1″) and even the slightly less expensive phones […]