From owner-freebsd-geom@FreeBSD.ORG Fri Sep 21 19:58:40 2007 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3DA3E16A417 for ; Fri, 21 Sep 2007 19:58:40 +0000 (UTC) (envelope-from softsearch@gmail.com) Received: from mu-out-0910.google.com (mu-out-0910.google.com [209.85.134.187]) by mx1.freebsd.org (Postfix) with ESMTP id B06AC13C48A for ; Fri, 21 Sep 2007 19:58:39 +0000 (UTC) (envelope-from softsearch@gmail.com) Received: by mu-out-0910.google.com with SMTP id w9so1052272mue for ; Fri, 21 Sep 2007 12:58:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=beta; h=domainkey-signature:received:received:date:from:reply-to:organization:x-priority:message-id:to:subject:in-reply-to:references:mime-version:content-type:content-transfer-encoding; bh=BcrRFI3YB6/nX+fYu8PxWmvJ95FOwaSgFFKnrU4qsfk=; b=Dy1avrRqgxPlmGg1jfLuYrdcadCtAgzdYxAvCsi/68/BsRCEP/nN/+QZhNAtoQh/cV2Bf/vPq9Pg7jpgskcB8XrceTgsvHQLnjJRQuo+kkHZKFMAI9BxF+gbr5ZpOGkESzZxEG1qZxxo1DYYD9/vo0rft0Ku6sKlrqAcoIZPm9M= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:date:from:reply-to:organization:x-priority:message-id:to:subject:in-reply-to:references:mime-version:content-type:content-transfer-encoding; b=rIMTu1eFZ2WhlLByexOZSetU7RdSyNreZ1QqUlUeXnhdn64eyTN39lIelqjNSQ2dL30Z1OVog/VtOlroKfi7DubUwomdLYoHzaofJT1tRohHu6u0to6hSxlbnuoZ3ABjcG5aUHimu3bPlaCL/uNOkogRFWd7scVgfWN7587v+QA= Received: by 10.82.114.3 with SMTP id m3mr1846882buc.1190404716121; Fri, 21 Sep 2007 12:58:36 -0700 (PDT) Received: from rover ( [83.222.4.74]) by mx.google.com with ESMTPS id f7sm2031081nfh.2007.09.21.12.58.32 (version=SSLv3 cipher=OTHER); Fri, 21 Sep 2007 12:58:34 -0700 (PDT) Date: Fri, 21 Sep 2007 23:58:02 +0400 From: Michael Monashev Organization: SoftSearch.ru X-Priority: 3 (Normal) Message-ID: <1310567292.20070921235802@gmail.com> To: Pawel Jakub Dawidek In-Reply-To: <20070921170506.GB9445@garage.freebsd.pl> References: <20070921143318.GC5690@garage.freebsd.pl> <20070921170506.GB9445@garage.freebsd.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Re[2]: raidtest for zfs X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Michael Monashev List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Sep 2007 19:58:40 -0000 Hello, Pawel. >> > > How to run raidtest ( >> > > http://www.freebsdsoftware.org/benchmarks/raidtest.html ) on zfs? >> > > >> > > diskinfo dos'n work. >> > >> > raidtest is for block device testing. If you want to test ZFS with it, >> > you need to create ZVOL with 'zfs create -V' command, eg. >> > >> > # zpool create tank raidz da{0,1,2,3,4} >> > # zfs create -V 100g tank/vol >> > # diskinfo -v /dev/zvol/tank/vol >> >> >> >> I get strange and fantastic results: >> >> > raidtest genfile -s 209715200 -S 512 -n 50000 -r -f >> File raidtest.data generated. >> Number of READ requests: 50000. >> Number of WRITE requests: 0. >> Number of bytes to transmit: 3279956992. >> >> > raidtest test -d /dev/zvol/tank/vol -n 10 >> Read 50000 requests from raidtest.data. >> Number of READ requests: 50000. >> Number of WRITE requests: 0. >> Number of bytes to transmit: 3279956992. >> Number of processes: 10. >> Bytes per second: 245146813 >> Requests per second: 3737 >> ^^^^^ - too big! >> >> > raidtest genfile -s 209715200 -S 512 -n 50000 -f >> File raidtest.data generated. >> Number of READ requests: 25046. >> Number of WRITE requests: 24954. >> Number of bytes to transmit: 3311506944. >> >> > raidtest test -d /dev/zvol/tank/vol -n 10 >> Read 50000 requests from raidtest.data. >> Number of READ requests: 25046. >> Number of WRITE requests: 24954. >> Number of bytes to transmit: 3311506944. >> Number of processes: 10. >> Bytes per second: 195043585 >> Requests per second: 2944 >> ^^^^^ - too big! >> >> >> The real results is: >> >> > raidtest test -d /dev/raid3/g3 -n 10 >> Read 50000 requests from raidtest.data. >> Number of READ requests: 50000. >> Number of WRITE requests: 0. >> Number of bytes to transmit: 3316146176. >> Number of processes: 10. >> Bytes per second: 11398078 >> Requests per second: 171 >> >> What is wrong? >> >> How to run raidtest correctly on /dev/zvol/tank/vol ? > Ok. Here it how it works. ZFS has this COW model. It doesn't preallocate > space. When you read blocks you never written, it won't touch the disks, > but will just return zeros. > To properly test read performance, you first need to write, so you > should first run raidtest with -w flag, then zpool export/import your > pool to remove cache and then retest with or without -r flag. I run: > raidtest test -d /dev/zvol/tank/vol -n 10 -w Read 50000 requests from raidtest.data. Number of READ requests: 0. Number of WRITE requests: 50000. Number of bytes to transmit: 3281546240. Number of processes: 10. Bytes per second: 120195634 Requests per second: 1831 > zpool export tank > zpool import tank > raidtest test -d /dev/zvol/tank/vol -n 10 -r Read 50000 requests from raidtest.data. Number of READ requests: 50000. Number of WRITE requests: 0. Number of bytes to transmit: 3281546240. Number of processes: 10. Bytes per second: 69264127 Requests per second: 1055 Results seems too strange again. How to turn off zfs cache completely? FreeBSD 7.0-CURRENT amd64 -- Michael