Re: [gentoo-amd64] Re: Is my RAID performance bad possibly due to starting sector value?

["Gary E. Miller" <gem@rellim.com>]

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Yo Duncan!

On Fri, 28 Jun 2013 00:20:45 +0000 (UTC)
Duncan <1i5t5.duncan@cox.net> wrote:

> > I have around 30 RAID1 sets in production right now.  Some of them
> > doing mostly reads and some mostly writes.  Some are HDD and some
> > SSD. The RAID sets are pushed pretty hard 24x7 and we watch the
> > performance pretty closely to plan updates.  I have collectd
> > performance graphs going way back.
> 
> So you're basically confirming it with normal usage as well, but have 
> documented performance history going pretty well all the way back.
> Not the simple test script I was hoping for, but pretty impressive,
> none-the- less.

I find that 'hdparm -tT', 'dd' and 'bonnie++' will match up pretty well
with what I see in production.  Just be sure to use really large test
file sizes with bonnie++ and dd. dd also needs a pretty large block size
(bs=) and pretty large/fast source of bits when writing.

With bonnie++ you can easily see the speed differences between raw disks
and various RAID types.


RGDS
GARY
---------------------------------------------------------------------------
Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97701
	gem@rellim.com  Tel:+1(541)382-8588

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