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From: Lukas Ertl <le@FreeBSD.org>
To: freebsd@newmillennium.net.au
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cc: freebsd-current@FreeBSD.org
Subject: Re: Gvinum RAID5 performance
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On Mon, 1 Nov 2004 freebsd@newmillennium.net.au wrote:

> Now, running a dd from a plex gives me less performance than running a
> dd from one of the subdisks, even though the array is not running in
> degraded mode.

I'd consider this normal behaviour, since you have to go through the 
offset calculation.

> 31237376, 31613728, 31990080, 32366432, 32742784, 33119136, <machine
> consistently locks up at this point>

This should be fixed with my latest commit to geom_vinum_plex.c.

> On a final note, I'd like to implement the ability to grow RAID5 plexes
> - any suggestions on where to start?

You need to relocate all parity stripes when you want to do that.

cheers,
le

-- 
Lukas Ertl                         http://homepage.univie.ac.at/l.ertl/
le@FreeBSD.org                     http://people.freebsd.org/~le/