This is a nice article, but possibly a bit dated and not really considering higher-end enterprise-scale subsystems that are available and more common these days, where RAID is not only obsolete, but not even a configuration option on the subsystem. Higher end arrays are now 'wide-striping' (as one term) across the entire array and are managed by the subsystem HW/FW/SW itself. Configuration is limited more to logical units and volumes. So although the discussion is valid for a more traditional physical server, I beleive more consideration needs to be placed on newer generation virtual compute modules with high-end disk subsystems. Also when reaching multi-terabyte/pedabyte scales, spindle counts are not much of a factor really either, each spindle possibly (typically) being a terabyte drive in itself. These systems are tuned and configured so differently than, say a local disk array, that I feel it warrants mention.
I'm finding many of the articles I recieve from SSCC are not considering true enterprise and large scale systems, focusing more on simpler stand-alone systems and may be misleading to newer adminstrators who might be working in enterprise level environements.
I'd love to start seeing more write-ups targeting higher profile systems, as that is where the leading edge of technology lives and where the real sticky intracacies tart getting interesting.
The RAID topics are great above, dont get me wrong, but it's just reminiscent of a era past.
But that's just one humble adminstrators opinion of course... it's always good to see folks writing and sharing knowledge of any kind, so keep up the work !