Featured articles

DevOps for the Sinclair Spectrum! A series of articles exploring a modern development environment for the classic 8-bit 1980s home computer

Back to the floppy: A musing on the passing of a once-common physical storage medium

Review of the Apollo Vampire 1200 v2 accelerator add-on card for the classic Amiga 1200 computer

Recent Posts

Poo

OK, I readily admit that this is really childish. I haven’t updated this site for ages; I know there are far better things that I could be writing about. At the age of nearly 30, I really shouldn’t be sniggering at naughty words like I’m back in primary school. But when I saw this unbelievably apt number plate on a sewage truck, I realised I had witnessed the stuff of playground legends. I present to you The Poo Truck in all it’s glory…

ZFS Replication

As I’ve been investigating ZFS for use on production systems, I’ve been making a great deal of notes, and jotting down little "cookbook recipies" for various tasks. One of the coolest systems I’ve created recently utilised the zfs send & receive commands, along with incremental snapshots to create a replicated ZFS environment across two different systems. True, all this is present in the zfs manual page, but sometimes a quick demonstration makes things easier to unders...

ZFS as a volume manager

While browsing the ZFS man page recently, I made an interesting discovery: ZFS can export block devices from a zpool, which means you can separate "ZFS the volume manager" from "ZFS the filesystem". This may well be old news to many; however I haven’t seen many references to this on the web, so thought I’d post a quick blog update.

ZFS and caching for performance

I’ve recently been experimenting with ZFS in a production environment, and have discovered some very interesting performance characteristics. I have seen many benchmarks indicating that for general usage, ZFS should be at least as fast if not faster than UFS (directio not withstanding - not that UFS directio itself is any faster, but anything that does it’s own memory management such as InnoDB or Oracle will suffer from the double-buffering effect unless ZFS has been tuned...

Apache mod_proxy balancing with PHP sticky sessions

I’ve been investigating the new improved mod_proxy in Apache 2.2.x for use in our new production environment, and in particular the built-in load balancing support. It was always possible to build a load-balanced proxy server with Apache before, using some mod_rewrite voodoo, but having a whole set of directives that do all the hard work for you is a great feature. There is however, a catch. It won’t work out of the box with PHP sessions, or many other applications. I’ve ...