Comments on: Basic RAID http://www.visiognomy.com/diagrams/archives/2005/02/24/basic-raid/ Life in diagrams. en Mon, 6 Feb 2012 02:44:36 +0000 http://wordpress.org/?v=1.2.2 by: James Wetterau http://www.visiognomy.com/diagrams/archives/2005/02/24/basic-raid/#comments Fri, 25 Feb 2005 14:23:15 -0500 10:17@http://www.visiognomy.com/diagrams It’s interesting to me that you didn’t go into a comparison of RAID-3, 4, 5, which is where I think the really interesting tradeoffs come up. What you said about RAID-5 basically applies to all three, with each one representing a different approach towards what should be fast (affecting all three of read, write, CPU demands). Basically, in a nutshell RAID-3 would be more appropriate for working on large files (e.g. multimedia) whereas RAID-5 would be more appropriate for transactional systems; databases, basically. I think a comparison among these is particularly well suited for diagramming, because you can illustrate the process of reading and writing, and what different kinds of parity calculation and different units of size (disk blocks vs. bytes) do to CPU use, disk head movement, etc. Perhaps you could a subsquent feature on those. It’s interesting to me that you didn’t go into a comparison of RAID-3, 4, 5, which is where I think the really interesting tradeoffs come up. What you said about RAID-5 basically applies to all three, with each one representing a different approach towards what should be fast (affecting all three of read, write, CPU demands). Basically, in a nutshell RAID-3 would be more appropriate for working on large files (e.g. multimedia) whereas RAID-5 would be more appropriate for transactional systems; databases, basically.

I think a comparison among these is particularly well suited for diagramming, because you can illustrate the process of reading and writing, and what different kinds of parity calculation and different units of size (disk blocks vs. bytes) do to CPU use, disk head movement, etc. Perhaps you could a subsquent feature on those.

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