Posts by TheComputerGeek

By: Jeff Johnston

IO Scheduling Improvements

Thanks to a new IO scheduler in Linux Kernel 2.6 it is possible to achieve speed increases on standard desktop style workloads of up to 1000% according to Andrew Morton of Open Source Development Labs (OSDL). The speed increase is thanks to the wait-before-seek function of the anticipatory scheduler that is one of two IO scheduling policies in kernel 2.6. The two scheduling systems were benchmarked against each other on a variety of diffent builds and systems by OSDL and you can see the results here.

Anticipatory Scheduler (AS)

The Anticipatory Scheduler attempts to anticipate future read requests from processes. Linus Torvalds, original creator of Linux, told me "Basically, the anticipatory scheduler maintains some per-process statistics to try to guess whether there will be another dependent read 'soon'" and if the algorithm guesses that there will be another read access it will wait before returning to process the next request. This significantly decreases the back and forth seeking under some loads. The wait-before-seek enables one process to perform several similar reads in rapid succession without having to send the drive head back and forth repeatedly. It is using the AS that Morton experienced 1000% speed increases.

Deadline Scheduler

This 1000% speed increase is only on standard desktop type work loads, but there is a way to get increased performance for database servers and high disk performance systems. As mentioned earlier the anticipatory scheduler is just one …

By: Jeff Johnston

Q: How secure are wireless routers for sharing internet between computers? - Carol in London Ontario

A: Wireless routers have received a lot of bad press lately. I have seen a number of reports on different news programs about the insecurity of wireless routers. The fact is wireless routers are secure if they are configured to be secure. The problem with security in wireless routers is that people generally don't configure them to ensure security. The perception tends to be that configuring a secure wireless network is too difficult. The fact is that most wireless routers comes with easy to follow instructions on how to enable encryption on the router to secure the network. If you follow the steps as laid out in the instructions for securing your network then your network is reasonably secure. By default a wireless router is wide open, which means that anyone can hack into your network.

You may think that no one would bother hacking into your home network, but the fact is people do just that. The process is called "War Driving". Basically the hacker drives around with a laptop and wireless network card, his laptop notifies him when it picks up a network connection that he can use and he parks his car and uses the newly found network connection. This allows the hacker to use your internet connection for whatever he wants, hacking into other systems and leaving a trace back to your network, …

Running a Home Web Server on a Budget
By Jeff Johnston

Running a web server from your home is not necessarily difficult or expensive. In order to run a home web server you need a fairly high-speed connection, a Domain name, a computer, an operating system, and an HTTP server. Of course anything you wish to add beyond that is up to you.

The first item, a high-speed connection, is probably going to be your highest cost. DSL will get you the most bandwidth for your buck though, and it is available in almost all North American markets now. You will have to ensure that your Internet Service Provider (ISP) knows that you intend to run a web server from your home so that your can get a dedicated IP, or at least have them set up their DNS to point your Domain Name to your computer. Generally speaking a dedicated IP is an additional price, but when dealing with accounts that are designed for servers it may not be.

Domain names are easy to acquire and not overly expensive, Go Daddy Software has what I believe is the cheapest domain name registration fees on the Internet. Fees on Go Daddy range from $7 - $10/year. But having a domain name is technically optional since there are many ways around having to pay that yearly fee. You could use only your IP address, but you would have to ensure that your ISP gives you …