Subject: Re: RaidFrame poor performance
To: None <current-users@NetBSD.org>
From: Matthias Scheler <email@example.com>
Date: 01/27/2005 00:45:20
In article <41F7C157.firstname.lastname@example.org>,
Jochen Keil <J.Keil@gmx.de> writes:
> The iozone benchmark are very interesting (at least for me). A 3 disk R5
> setup (with two usable disks) set up with a correct stripe/fs block size
> is about 4 times faster than a 4 disk R5 (3 usable disks) setup.
What's surprising about that? On a 3 disk RAID 5 you need 3 reads and
3 writes for 1 write to the RAID. On a 4 disk RAID 5 you need 4 of them.
Matthias Scheler http://scheler.de/~matthias/