[nycbug-talk] Fwd: Adaptec AAC raid support

Marco Scoffier marco
Mon Mar 21 16:39:02 EST 2005


On Mon, Mar 21, 2005 at 03:57:28PM -0500, Marco Scoffier wrote:
>On Mon, Mar 21, 2005 at 03:31:10PM -0500, bruno wrote:
>>If you do need performance software raid is sometimes not enough.
>>
>I was wondering if anyone had numbers on this.  Are we talking +5% cpu
>utilisation and -5% throughput or +20% and -20% or more ??  Searched a bit for
>numbers but came up dry.

ok found: 

http://marc.theaimsgroup.com/?l=openbsd-misc&m=110665117301231&w=2

Which compares raw disk with a raid5 and gets a ~10% cpu increase when running
the raid.  Does not compare a raid controller firmware managed raid vs kernel
level openbsd raidctl managed raid5.  I guess it is too hard to setup, unless
someone is making boxes everyday, and has lots of similar hardware to test out.

and 

http://www.daemonnews.org/200005/raidframe.html

nice article about raidframe performance, but no comparisons.  Uses the nice
bonnie test : http://www.textuality.com/bonnie/

I understand its the knee jerk reaction to say hardware is faster, but knowing
exactly how much faster helps to color the decision.  Especially considering
the drawback of not-even ncurses based, bios-like interface of most firmware
raidcontroller software.

-- 
Marco




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