From owner-freebsd-scsi Fri Feb 12 08:10:36 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id IAA00371 for freebsd-scsi-outgoing; Fri, 12 Feb 1999 08:10:36 -0800 (PST) (envelope-from owner-freebsd-scsi@FreeBSD.ORG) Received: from panzer.plutotech.com (panzer.plutotech.com [206.168.67.125]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id IAA00361 for ; Fri, 12 Feb 1999 08:10:31 -0800 (PST) (envelope-from ken@panzer.plutotech.com) Received: (from ken@localhost) by panzer.plutotech.com (8.9.2/8.8.5) id JAA34695; Fri, 12 Feb 1999 09:10:24 -0700 (MST) From: "Kenneth D. Merry" Message-Id: <199902121610.JAA34695@panzer.plutotech.com> Subject: Re: It%s not the write cache on 3.0-STABLE and not tagged comma In-Reply-To: from Matthew Jacob at "Feb 12, 1999 8: 3:52 am" To: mjacob@feral.com Date: Fri, 12 Feb 1999 09:10:24 -0700 (MST) Cc: ANDREAS.KLEMM.AK@bayer-ag.de, scsi@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL43 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Matthew Jacob wrote... > > Is read performance okay? > Also what's "poor"? Read performance is fine. (about 12MB/sec) "poor" means between 1 and 3MB/sec. I'll forward you his original mail, I think it probably got nuked by Majordomo's message size filter. > On Fri, 12 Feb 1999, Kenneth D. Merry wrote: > > > Matthew Jacob wrote... > > > > > > What was the problem? > > > > He is getting poor performance for sequential writes with a Seagate disk > > under CAM. Write throughput to the disk is fairly erratic. (i.e., lots of > > ups and downs) > > > > He has the problem under 2.2.7 with tagged queueing enabled, but not when > > he disables tagged queueing. The problem occurs under 3.0 with or > > without tagged queueing. > > > > I told him to disable write caching, since I have seen similar problems > > when write caching is enabled, but that didn't seem to fix the problem. > > > > Any ideas? > > > > Ken > > -- > > Kenneth Merry > > ken@plutotech.com > > Ken -- Kenneth Merry ken@plutotech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message