From owner-freebsd-questions Wed May 9 21: 4:31 2001 Delivered-To: freebsd-questions@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 20BEB37B424 for ; Wed, 9 May 2001 21:04:27 -0700 (PDT) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 675596ACBC; Thu, 10 May 2001 13:34:25 +0930 (CST) Date: Thu, 10 May 2001 13:34:25 +0930 From: Greg Lehey To: Scott Mace Cc: Dan Phoenix , FreeBSD Questions Subject: Re: vinum on 2 ide drives? Message-ID: <20010510133425.K56501@wantadilla.lemis.com> References: <20010510125406.I56501@wantadilla.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from smace@intt.org on Wed, May 09, 2001 at 10:46:43PM -0500 Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.lemis.com/~grog X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wednesday, 9 May 2001 at 22:46:43 -0500, Scott Mace wrote: > I'm seeing the same behaviour with a pair of IBM drives. I even made sure > that > write cache was enabled... I'm using 307030's > > This is on a regular non-vinum partition > > onix2# iozone 128 8192 > > IOZONE: Performance Test of Sequential File I/O -- V2.01 (10/21/94) > > IOZONE writes a 128 Megabyte sequential file consisting of > 16384 records which are each 8192 bytes in length. > It then reads the file. It prints the bytes-per-second > rate at which the computer can read and write files. This is not really relevant to real-life access. But it might explain Dan's issues: sequential access to a stripe will be slower than to a concat plex such as you're using. > IOZONE performance measurements: > 21746669 bytes/second for writing the file > 29671622 bytes/second for reading the file > > This is on a vinum mirror. > > IOZONE performance measurements: > 10784600 bytes/second for writing the file > 24437936 bytes/second for reading the file It's difficult to guess what's going on here. Looking at your configuration below, I'd guess that you're not comparing things directly. > drive vinumdrive0 device /dev/ad0s1e > drive vinumdrive2 device /dev/ad0s1f > drive vinumdrive4 device /dev/ad0s1g > drive vinumdrive1 device /dev/ad1s1e > drive vinumdrive3 device /dev/ad1s1f > drive vinumdrive5 device /dev/ad1s1g These are four drives too many. You don't want more than one drive per spindle. Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message