From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 643AC1381F3 for ; Fri, 28 Jun 2013 00:21:11 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 08354E09D7; Fri, 28 Jun 2013 00:21:06 +0000 (UTC) Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 31AE4E09CD for ; Fri, 28 Jun 2013 00:21:05 +0000 (UTC) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1UsMQw-0000ow-NE for gentoo-amd64@lists.gentoo.org; Fri, 28 Jun 2013 02:21:02 +0200 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 28 Jun 2013 02:21:02 +0200 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 28 Jun 2013 02:21:02 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-amd64@lists.gentoo.org From: Duncan <1i5t5.duncan@cox.net> Subject: [gentoo-amd64] Re: Is my RAID performance bad possibly due to starting sector value? Date: Fri, 28 Jun 2013 00:20:45 +0000 (UTC) Message-ID: References: <20130621115043.32b99d94.gem@rellim.com> <20130622151516.7d0be796.gem@rellim.com> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-amd64@lists.gentoo.org Reply-to: gentoo-amd64@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: ip68-231-22-224.ph.ph.cox.net User-Agent: Pan/0.140 (Chocolate Salty Balls; GIT 368aae4 /usr/src/portage/src/egit-src/pan2) X-Archives-Salt: 4017855c-7fd5-49b1-880c-472cb2ab54ac X-Archives-Hash: 1df16918d98f22e36e0241c0a938591a Gary E. Miller posted on Sat, 22 Jun 2013 15:15:16 -0700 as excerpted: >> >> [Does md/raid1 do parallel reads of multiple files at once?] >> > >> > It surely does. I have confirmed that at least monthly since md has >> > existed in the kernel. >> >> Out of curiosity, /how/ do you confirm that? I agree based on real >> usage experience, but with a claim that you're confirming it at least >> monthly, it sounds like you have a standardized/scripted test, and I'm >> interested in what/how you do it. > > I have around 30 RAID1 sets in production right now. Some of them doing > mostly reads and some mostly writes. Some are HDD and some SSD. > The RAID sets are pushed pretty hard 24x7 and we watch the performance > pretty closely to plan updates. I have collectd performance graphs > going way back. So you're basically confirming it with normal usage as well, but have documented performance history going pretty well all the way back. Not the simple test script I was hoping for, but pretty impressive, none-the- less. Thanks. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman