Date: Tue, 05 Sep 2000 16:39:48 -0700 From: Mike Smith <msmith@freebsd.org> To: Greg Lehey <grog@lemis.com> Cc: Mike Tancsa <mike@sentex.net>, Tim Tsai <tim@futuresouth.com>, stable@FreeBSD.ORG Subject: Re: Vinum (was: RAID) Message-ID: <200009052339.QAA03602@mass.osd.bsdi.com> In-Reply-To: Your message of "Wed, 06 Sep 2000 08:48:35 %2B0930." <20000906084835.B21113@wantadilla.lemis.com>
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> > Just about to test and compare the same Atlas IV drives (QUANTUM ATLAS IV 9 > > WLS 0B0B) usings a 2940U2 (aic7890/91) with vinum. I will post the results > > with the same three SCSI drives in the various adaptors in RAID5 (3 drive > > config) when done. > > Please make sure to use rawio in the tests. Other things, such as > bonnie and dd, give better looking results, but they're not very > related to what happens in practice. Rawio is largely a seek-time tester, and not particularly representative of real-world I/O loads either. To get a feel for how a controller interacts with the buffer cache, you need to present the load via the filesystem. I typically use a large number of bonnie processes (20 or so) working with large datasets (1-10GB) and then ignore their output and instead monitor the controller's throughput using devstat. Other filesystem load generators are probably worth considering as well, since bonnie's I/O patterns are not very imaginiative. -- ... every activity meets with opposition, everyone who acts has his rivals and unfortunately opponents also. But not because people want to be opponents, rather because the tasks and relationships force people to take different points of view. [Dr. Fritz Todt] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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