From owner-freebsd-hackers@FreeBSD.ORG Tue Jan 15 20:29:03 2013 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 2758CF00 for ; Tue, 15 Jan 2013 20:29:03 +0000 (UTC) (envelope-from fodillemlinkarim@gmail.com) Received: from mail-ie0-f171.google.com (mail-ie0-f171.google.com [209.85.223.171]) by mx1.freebsd.org (Postfix) with ESMTP id F12BA6B7 for ; Tue, 15 Jan 2013 20:29:02 +0000 (UTC) Received: by mail-ie0-f171.google.com with SMTP id 17so1039988iea.16 for ; Tue, 15 Jan 2013 12:29:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:message-id:date:from:user-agent:mime-version:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=cqY7iluOoqEf+EC26iQaOz0FcqnwHnDiAVI9+q8EA7g=; b=Kkl4WMUx0nAP9uZrbyM5w9SXoyYoh2Ozl+TZ8npOiR22lW9wt+vcwOd2AsuCXweuUu RfrFcdYyb9obdaAj4k66W1sqYYoc29nemGZO8rG2UGCUIAjhmKHpchh/Hq5K/8WV103s HSHxt7IW5vaxAhe+lDvodcFIAqid/M9SQMJ1P/7FVv5uioefl7NWoupmVdP4rrVb7pwE FcBQsrd+TO8/7O4vMsfzB4LkadtRPZ8M5wmPuFhjb0/nu+WLnta50GCwHSt1/LpFfuGf cqKeQB0sAbQQKxQQm3WkBPPd3MG1OywCxO0kb4yEY5HLif+Y3/L+74TgIciCHGiWuZWG lplA== X-Received: by 10.50.41.136 with SMTP id f8mr2399283igl.105.1358281742050; Tue, 15 Jan 2013 12:29:02 -0800 (PST) Received: from [192.168.1.73] ([208.85.112.101]) by mx.google.com with ESMTPS id ez8sm2901215igb.17.2013.01.15.12.28.59 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 15 Jan 2013 12:29:00 -0800 (PST) Message-ID: <50F5BC08.1060700@gmail.com> Date: Tue, 15 Jan 2013 15:28:56 -0500 From: Karim Fodil-Lemelin User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130107 Thunderbird/17.0.2 MIME-Version: 1.0 CC: freebsd-hackers@freebsd.org Subject: Re: IBM blade server abysmal disk write performances References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Tue, 15 Jan 2013 20:43:35 +0000 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Jan 2013 20:29:03 -0000 On 15/01/2013 3:03 PM, Dieter BSD wrote: > Disabling the disks's write cache is *required* for data integrity. > One op per rev means write caching is disabled and no queueing. > But dmesg claims "Command Queueing enabled", so you should be getting > more than one op per rev, and writes should be fast. > Is this dd to the raw drive, to a filesystem? (FFS? ZFS? other?) > Are you running compression, encryption, or some other feature > that might slow things down? Also, try dd with a larger block size, > like bs=1m. Hi, Thanks to everyone that answered so far. Here is a follow up. dd to the raw drive and no compression/encryption or some other features, just a naive boot off a live 9.1 CD then dd (see below). The following results have been gathered on the FreeBSD 9.1 system: # dd if=/dev/zero of=toto count=100 100+0 records in 100+0 records out 51200 bytes transferred in 1.057507 secs (48416 bytes/sec) # dd if=/dev/zero of=toto count=100 bs=104 100+0 records in 100+0 records out 10400 bytes transferred in 1.209524 secs (8598 bytes/sec) # dd if=/dev/zero of=toto count=100 bs=1024 100+0 records in 100+0 records out 102400 bytes transferred in 0.844302 secs (121284 bytes/sec) # dd if=/dev/zero of=toto count=100 bs=10240 100+0 records in 100+0 records out 1024000 bytes transferred in 2.173532 secs (471123 bytes/sec) # dd if=/dev/zero of=toto count=100 bs=102400 100+0 records in 100+0 records out 10240000 bytes transferred in 19.915159 secs (514181 bytes/sec) # dd if=/dev/zero of=toto count=100 100+0 records in 100+0 records out 51200 bytes transferred in 1.070473 secs (47829 bytes/sec) # dd if=/dev/zero of=foo count=100 100+0 records in 100+0 records out 51200 bytes transferred in 0.683736 secs (74883 bytes/sec) # dd if=/dev/zero of=foo count=100 bs=1024 100+0 records in 100+0 records out 102400 bytes transferred in 0.682579 secs (150019 bytes/sec) # dd if=/dev/zero of=foo count=100 bs=10240 100+0 records in 100+0 records out 1024000 bytes transferred in 2.431012 secs (421224 bytes/sec) # dd if=/dev/zero of=foo count=100 bs=102400 100+0 records in 100+0 records out 10240000 bytes transferred in 19.963030 secs (512948 bytes/sec) # dd if=/dev/zero of=foo count=10 bs=1024000 10+0 records in 10+0 records out 10240000 bytes transferred in 19.615134 secs (522046 bytes/sec) # dd if=/dev/zero of=foo count=1 bs=10240000 1+0 records in 1+0 records out 10240000 bytes transferred in 19.579077 secs (523007 bytes/sec) Best regards, Karim.