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Re: [SAGE] NetApp--spindles vs. performance
These days, with 10K RPM disks, as long as there are "enough" spindles,
the potential difference between N 72G disks and N*2 36 GB disks on
a filer doesn't really affect performance.
the number of FC loops, the number of GigE conenctions, the cache size
and the CPU and (of course) your workload, will tell.
as for a rule of thumb, with 72 GB disks I try for raid group sizes of
9 spindles. to get 1 TB usable, you'll need at least 16 spindles,
which means two ds14 disk shelves. with two 9-disk raid groups and
a hot spare, (19) disks, there will be room to add spindles to the shelves.
get two Fiberchannel adapters, or one dual-port FC adapter, to provide
two FC loops.
an 810 with two FC loops and 18 active disks will run out of CPU *long*
before it runs out of spindle ops.
-skottie
Guy B. Purcell wrote:
> I'm posting this for a friend, whom I hope to be working with very soon :^)
>
> He's specing out a NetApp filer (F810, I believe), and would like to
> know if anyone has any real experience with (or even well-educated
> guesses about) the performance gain of using 36 GB disks instead of 72
> GB disks. The intended use will be about 50/50 for typical PC
> office-type files & Oracle DBs.
>
> He needs to balance maximizing performance against minimizing cost.
> Using 36 GB disks costs more (need twice as many disks to achieve the 1
> TB storage goal), but that might be offset by significant performance
> gains from having twice as many spindles. Are there rules of thumb for
> this sort of thing in general? There must be some point of diminishing
> returns with shrinking disk size to increase spindle count (would that I
> had a system to experiment with!). Thanks!
>
> --
> Guy
> (guy@extragalactic.net)
>
> Sysadmin for hire <http://www.extragalactic.net/guy/resume.html>
>
>
--
Scott Miller | Animation Technology
work: skottie@dreamworks.com | Dreamworks Feature Animation
life: skottie@pobox.com