That's more along the lines of what kind of info I'm digging for - but
doesn't quite address how one goes about coming up with a number or size.
There may not be a "right" or "single" answer however you must admit there
is a generalized "right" answer. Consider for example that while RAID-5
arrays can vary in the # of disks assigned and size of them, there is a
generalized rule of thumb as Cordiali pointed out. Too few or too many disks
in your RAID-5 array and you can have performance implications. There's a
sort of sweet spot for creating RAID-5 arrays and keeping that in mind there
should also be a similar sweet spot in how many volumes one might want to
assign. All in all though I still wonder if it really matters a whole lot..
Whether you have 1 write going on or 10, you're still striping across the
array and I question whether you'd really see much difference one way or
another. Might be an interesting thing to try various variants of..

Regards,

Gerald Wichmann
Senior Systems Development Engineer
Zantaz, Inc.
925.598.3099 (w)