From owner-freebsd-scsi Tue Apr 14 18:51:02 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA13809 for freebsd-scsi-outgoing; Tue, 14 Apr 1998 18:51:02 -0700 (PDT) (envelope-from owner-freebsd-scsi@FreeBSD.ORG) Received: from misery.sdf.com (misery.sdf.com [204.244.213.32]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id BAA13770 for ; Wed, 15 Apr 1998 01:50:53 GMT (envelope-from tom@sdf.com) Received: from tom by misery.sdf.com with smtp (Exim 1.82 #3) id 0yPGwg-0000UW-00; Tue, 14 Apr 1998 18:25:02 -0700 Date: Tue, 14 Apr 1998 18:24:49 -0700 (PDT) From: Tom To: bh@epigram.com cc: freebsd-scsi@FreeBSD.ORG Subject: Re: RAID performance/benchmarking In-Reply-To: <3533BBE4.DF09519@epigram.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, 14 Apr 1998, Brandon Huey wrote: > Dell PowerEdge 4200/300, 96MB RAM, 3 9GB Seagate Barracuda SCA drives > DPT PM3334UW w/64MB cache > > FreeBSD 2.2.6 > DPT kernel options: DPTOPT > DPT_MEASURE_PERFORMANCE > DPT_FREELIST_IS_STACK > > i created an array group with the dos util 'dptmgr' from default > settings. > > using IOZONE and Bonnie, i create a 128MB file for read/write > benchmarking. > > i am aware of the performance implications of RAID-5, but I am getting > about 2MByte/sec max write transfer rate compared with 19MByte/sec on > reads. > > For a pci ultrawide controller, are these figures suspect? What kind of > write performance hit should one expect w/RAID-5 ? No, those figures are typical for RAID5 on the DPT PM334 when used with the default stripe size. However, do you want to optimize your system for bonnie/iozone (sequentional and single-user)? If so, there are lot of things you can change. However, then random-access, multi-user things don't benchmark well! I have a DPT PM334UW in a mail server with a 5 disk RAID5 array, and I'm constantly amazed about how well it performs real-world tasks. Tom To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message