From owner-freebsd-stable Sun Apr 19 22:34:29 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id WAA03525 for freebsd-stable-outgoing; Sun, 19 Apr 1998 22:34:29 -0700 (PDT) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from antipodes.cdrom.com (castles147.castles.com [208.214.165.147]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id FAA03490 for ; Mon, 20 Apr 1998 05:34:24 GMT (envelope-from mike@antipodes.cdrom.com) Received: from antipodes.cdrom.com (localhost [127.0.0.1]) by antipodes.cdrom.com (8.8.8/8.8.5) with ESMTP id WAA04185; Sun, 19 Apr 1998 22:31:39 -0700 (PDT) Message-Id: <199804200531.WAA04185@antipodes.cdrom.com> X-Mailer: exmh version 2.0zeta 7/24/97 To: Berend de Boer cc: "'Mike Smith'" , "stable@FreeBSD.ORG" Subject: Re: best sd0 flags ? (was wdc0) In-reply-to: Your message of "Sat, 18 Apr 1998 21:11:14 +0200." <01BD6B0E.863498B0.berend@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Sun, 19 Apr 1998 22:31:37 -0700 From: Mike Smith Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk > On Saturday, April 18, 1998 6:46 PM, Mike Smith [SMTP:mike@smith.net.au] > wrote: > > > > We've been duplicating 3GB Western Digital disks the last few days under > > 2.2.6, flags 0x80ff80ff on 166MHz P5/430TX boards, and averaging about > > 5M/sec throughput. Try 'dd if=/dev/wd1 of=/dev/null bs=1m' to get an > > idea of your raw disk speed as opposed to filesystem throughput. > > Hmm, something is seriously wrong here it seems. I've a Pentium II, 233MHz, > 128MB, Adaptec Ultra Wide SCSI and SCSI 2 4GB IBM drive. Using the above > code I get an average of 2MB. Is there something seriously wrong with this > system? And how can I tune it? As Bruce mentioned, you should use the raw device: azaria# dd if=/dev/sd1 of=/dev/null bs=1m count=20 20+0 records in 20+0 records out 20971520 bytes transferred in 9.182458 secs (2283868 bytes/sec) azaria# dd if=/dev/rsd1 of=/dev/null bs=1m count=20 20+0 records in 20+0 records out 20971520 bytes transferred in 2.571084 secs (8156684 bytes/sec) for a similar configuration (DCAS34330UW, PII/337, AHA2940UW) -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message