From owner-freebsd-hackers Thu Apr 6 22:19:48 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id WAA23028 for hackers-outgoing; Thu, 6 Apr 1995 22:19:48 -0700 Received: from xi.dorm.umd.edu (xi.dorm.umd.edu [129.2.140.12]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id WAA23022 for ; Thu, 6 Apr 1995 22:19:47 -0700 Received: (from smpatel@localhost) by xi.dorm.umd.edu (8.6.11/8.6.9) id BAA00747; Fri, 7 Apr 1995 01:19:39 -0400 Date: Fri, 7 Apr 1995 01:19:39 -0400 (EDT) From: Sujal Patel X-Sender: smpatel@xi.dorm.umd.edu To: "Rodney W. Grimes" cc: hackers@FreeBSD.org Subject: Re: large filesystems/multiple disks [RAID] In-Reply-To: <199504070516.WAA06264@gndrsh.aac.dev.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: hackers-owner@FreeBSD.org Precedence: bulk On Thu, 6 Apr 1995, Rodney W. Grimes wrote: > Did you have spindle sync on the Quantum drives? This is very important > if you want to eliminate rotational delay problems when muxing the > data out to the drive. You also need to have the interleave data chunk > match closely to the drive cache size (or smaller, but not to small). Unfortuantly, The Quantum drives do not support spindle sync. and also they only have a 96k cache on them too. > Your choice of controllers was poor. I have run 2 drives on a 1742 > doing iozone to both drives at the same time (3+MB/sec each drive) > for a controller throughput of 6MB/sec. > I have run 2 4MB/sec drives on an NCR 825 based controller and got > 7+MB/sec combined throughtput. It's possible that the controller is at fault here. Even though it is a EISA controller, it's very old-- I've had mine for many years. Sujal