Managing RAID on Linux

Making Sense of It All

In the final section of this chapter, I’d like to present an example RAID system that I built using parts available at most decent computer stores and online retailers.

The system in question was designed to replace a medium-volume web server that hosts content for video game enthusiasts. The original server was homegrown and quickly became inadequate as the site grew in popularity and moved out of its owner’s workplace into a collocation facility. Connecting the system to a larger network pipe solved many of its initial problems, but eventually, the hardware itself became overworked.

The site is mostly static, except for a few moderators who post new articles and reviews each day. It’s essential that the site have a 24 × 7 uptime, so RAID-0 is out of the question. And with my budget, RAID-1 wouldn’t work either, because the site frequently distributes large video clips and demos of upcoming games. I simply couldn’t afford the extra disks RAID-1 would require. That left RAID-5 as the best option.

In building the new RAID system, I needed to select a motherboard first because the old 32-bit PCI board was causing most of the performance problems on the original server. Because I was interested in high performance, I chose a motherboard that had two 64-bit PCI slots. Each of these 64-bit slots had a dedicated data bus with a throughput of 533 MB/s. (Remember that 64-bit PCI boards run at 66 MHz [66.6 million cycles per second * 8 bytes per cycle = 533 MB/s]). The ...