Re: RAID recommendations

Someone recently asked me why I like RAID10 over RAID5 and I finally came up with an appropriate analogy to illustrate the point. So here for your entertainment: Everyone knows that I am a devoted fan of RAID10. It provides the highest level of data safety, read and write performance, and recovery time performance all in one package. I will NEVER understand anyone selecting RAID5 these days with storage media so cheap! With 146GB 10000RPM drives < $1000US and 36GB 10000RPM drives ~ $300US how can you justify a 50% reduction in write performance to save a few bucks that amortize over 5years or so (the safety and recovery issues which are FAR more important aside)? If disk $$$ are really so dear I'd go for RAID3 or RAID4. Here's an analogy to explain my understanding of the RAID10 versus RAID10 issue at a gut level: Its like your car dealer offered you the option of a cheaper 5 cylinder engine over the standard V8 to save 25% on the engine cost. It uses the same gas, gets the same mileage in the city and only slightly less than the V8 on the highway, top speed is the same as is flatland accelleration, but the car will slow down by 50% when you climb a hill. Oh and BTW, here's the best part, it works great when it's working and if one cylinder fails it can continue to run on only 4 and a competent mechanic can even repair that one while the engine is still running! However, if it loses a second cylinder, even to a simple spark plug failure, before the first is fixed, then the engine will seize permanently and become 400 pounds of iron junk likely throwing the car, you and your family into a ditch to suffer life threatening injury. And folk JUMP at the chance! Ahh well. Art S. Kagel sending to informix-list