my web 0.2 website

When you build a KVM guest, if you want to install the guest over the network, you should attach the video console of your guest to a VNC display.
How can I put this..? This is quite a novel way of doing it.  I think there’s a reason that more virtualisation systems don’t work in this […]

I have been fairly consistently telling people a lie for the last ten years - and that is that Round Robin DNS can not be used for high availability. Its a view I have held pretty strongly, but two people have shown me techniques in the last week that have made me change my […]

Clever Dave likes Parallels for development, but doesn’t like that it is a cpu hog. An idle vm swallowed up 40-50% of cpu on his new Macbook.
He had the idea that reducing the speed of the kernel clock to 100MHz might make the idle vm less resource hungry, so we tested it out. Changing […]

I’m at LRL (currently watching Ted Haeger’s talk), and I am publishing my notes for my talk tomorrow, “Scaling Up for Champions”.
There are quite a lot of config examples in the notes which aren’t on the slides to support the talk.
Overview:

Definition of Scaling & Problems of scaling
You have to monitor things
Scaling individual machines - Disk […]

I hate cacti. Sorry guys, there are lots of things that are good about it, and those things are that if you want to monitor just switch/router interface stats, via snmp, and that’s *it*, its very easy. When you want to plot technical data that you source through something other than snmp, working […]

I am testing out Adaptive Readahead in Linux quite a lot at the minute. ARA offers particular performance improvements to file-reading logic, and should give significant performance wins on database servers.
I now have a stable enough kernel package for Debian users who may want to try it out. The kernel package uses the […]

To end a flurry of articles about Xen, here’s a rip from my notebook which explains how I managed to build Xen virtual machines under Debian. Comments on this process are very much welcome.
Install Debian 3.1 on your computer. I’ve typically wanted to keep my desktop Xen free, mainly because it does enough […]

I’ve just had to solve a problem that a lot of people have seen; but it seems like a lot of people who offer support on the Xen list were not able to come up with the answer.
When you boot a Xen guest from a disk image on your host, you use a loopback ‘instance’. […]

Xen is commonly used to describe a package of tools which can build a high-powered, low cost virtualisation environment. Virtualisation allows one computer to run several ‘instances’ of other computers, and permits systems administrators to run hundreds of test, staging, or development environments on a relatively small number of devices.
I will cover how to setup […]