Subject: Re: RAID tuning
To: NetBSD Users <firstname.lastname@example.org>
From: Chuck Yerkes <email@example.com>
Date: 12/19/2002 14:07:55
Quoting Jukka Marin (firstname.lastname@example.org):
> What does the following mean (output from systat):
> Discs wd4 wd5 cd0 wd0 wd1 fd0 md0 raid 64 fmin
> seeks 85 ftarg
> xfers 138 137 128 itarg
> Kbyte 1256 1249 1256 523 wired
> %busy 3.2 2.4 94.4 pdfre
> Why is raid 94.4% busy when the components (wd0, wd1) are only 3%
> busy? CPU is about 90% idle.
echo 3.2 2.4 94.4 + + p | dc
gives me 100%.
Coincidence? Doubtful. Perhaps its that most of the
work happens through the RAID 'device'?
and there was a little direct activity on boot?
That said, stripe width will depend on how/what you use it for.
Otherwise, I tend to use hardware raid, so can't offer more.