From owner-freebsd-questions@FreeBSD.ORG Tue Dec 2 01:26:12 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8E02C16A4CE for ; Tue, 2 Dec 2003 01:26:12 -0800 (PST) Received: from dot.freshdot.net (dot.freshdot.net [195.64.80.165]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3F8A443FCB for ; Tue, 2 Dec 2003 01:26:09 -0800 (PST) (envelope-from ssm+fbsd-questions@freshdot.net) Received: from ssmeenk by dot.freshdot.net with local (Exim 4.24) id 1AR6nI-0005nL-Fm for freebsd-questions@freebsd.org; Tue, 02 Dec 2003 10:26:08 +0100 Date: Tue, 2 Dec 2003 10:26:08 +0100 From: Sander Smeenk To: freebsd-questions@freebsd.org Message-ID: <20031202092608.GA16710@freshdot.net> Mail-Followup-To: freebsd-questions@freebsd.org References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.4i Subject: Re: Vinum & U320 SCSI, slower than UDMA100 IDE ? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 02 Dec 2003 09:26:12 -0000 Quoting Greg 'groggy' Lehey (grog@freebsd.org): > >Then I did a read test, like this: > >>date;find . -type f|while read FILE;do cat "$FILE" > > >>/dev/null;done;date > >I know it's not the most sophisticated test, but at least it shows that > >on the IDE disk, this 'test' took 24 seconds to complete. On the RAID10 > >array it took a whopping 73 seconds to complete. > You shouldn't expect any performance improvement with this kind of > test, since you still need to access the data, and there's no way to > do it in parallel. I knew it wasn't the best way to test, but I did expect it to be at least as fast as the same test on the same data on a IDE disk. And luckily, you agree ;) > >> plex org striped 3841k > You should choose a stripe size which is a multiple of the block size > (presumably 16 kB). Not doing so will have a minor performance > impact, but nothing like what you describe here. I might have misunderstood, but on the vinumvm.org website there is quite a comprehensive discussion on stripesizes and they conclude that larger stripesizes help increase throughput. They also discuss the size not being a power of 2, because that might cause stripes to end up on the same disk, which decreases performance... > >>ahd1: PCI error Interrupt > >>>>>>>>>>>>>>>>>>>>Dump Card State Begins <<<<<<<<<<<<<<<<< > >>ahd1: Dumping Card State at program address 0x94 Mode 0x22 > This is possibly related. Does it happen every time? It did, until I compiled a new 4.9 kernel from the 4.9-RELEASE src/ tree from CVS. (Thanks to Scott Long for pointing that out). The driver for aic7xxx cards was fixed, and now the message is gone, and the system is once again stable. I didn't notice any real change in performance yet. > The first thing to do is to find whether it's Vinum or the SCSI disks. > Can you test with a single SCSI disk (of the same kind, preferably one > of the array) instead of a single IDE disk? I did some tests, this time with Bonnie++, on vinum, scsi, ide, and vinum with big stripes and small stripes. I'm busy comparing them ;) But still, I doubt if bonnie++ is a good test, and I have a hard time interpreting the results. I can publish the results somewhere, in a while. Thanks, Sander. -- | Coffee (n.), a person who is coughed upon. | 1024D/08CEC94D - 34B3 3314 B146 E13C 70C8 9BDB D463 7E41 08CE C94D