Subject: Re: 3ware RAID controller slow?
To: Bill Stouder-Studenmund <>
From: Jukka Marin <>
List: netbsd-users
Date: 10/30/2007 19:39:41
On Tue, Oct 30, 2007 at 08:49:01AM -0700, Bill Stouder-Studenmund wrote:
> > Then why is RAID5 slow and a plain disk isn't (when extracting the same
> > pkgsrc tarball)?  I'm trying to find out whether I can use RAID5 or not,
> > that's why I'm asking ;)
> What could be happening is that you're doing a lot of RMW operations when 
> you write metadata. They are slow and add synchronous reads into important 
> i/o points.

That could be it - after the RAID controller and the disks run out of buffer

> > (Although I need to find a way to break the 2 TB disklabel barrier first..)
> Disklabels don't break 2 TB. That's why we have wedges.

Could someone please provide a pointer to a wedge tutorial?  Please? :-)