From owner-freebsd-hackers@FreeBSD.ORG Wed Jan 16 07:20:49 2013 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 6B69E6C5 for ; Wed, 16 Jan 2013 07:20:49 +0000 (UTC) (envelope-from wojtek@wojtek.tensor.gdynia.pl) Received: from wojtek.tensor.gdynia.pl (wojtek.tensor.gdynia.pl [188.252.31.196]) by mx1.freebsd.org (Postfix) with ESMTP id 6664EEAA for ; Wed, 16 Jan 2013 07:20:48 +0000 (UTC) Received: from wojtek.tensor.gdynia.pl (localhost [127.0.0.1]) by wojtek.tensor.gdynia.pl (8.14.5/8.14.5) with ESMTP id r0G7KkOf004574; Wed, 16 Jan 2013 08:20:46 +0100 (CET) (envelope-from wojtek@wojtek.tensor.gdynia.pl) Received: from localhost (wojtek@localhost) by wojtek.tensor.gdynia.pl (8.14.5/8.14.5/Submit) with ESMTP id r0G7Kktj004571; Wed, 16 Jan 2013 08:20:46 +0100 (CET) (envelope-from wojtek@wojtek.tensor.gdynia.pl) Date: Wed, 16 Jan 2013 08:20:46 +0100 (CET) From: Wojciech Puchar To: Karim Fodil-Lemelin Subject: Re: IBM blade server abysmal disk write performances In-Reply-To: <50F601D2.3090009@gmail.com> Message-ID: References: <50F5BC08.1060700@gmail.com> <50F601D2.3090009@gmail.com> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.2.7 (wojtek.tensor.gdynia.pl [127.0.0.1]); Wed, 16 Jan 2013 08:20:46 +0100 (CET) Cc: freebsd-hackers@freebsd.org 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: Wed, 16 Jan 2013 07:20:49 -0000 > Transfer rates: > outside: 102400 kbytes in 0.685483 sec = 149384 kbytes/sec > middle: 102400 kbytes in 0.747424 sec = 137004 kbytes/sec > inside: 102400 kbytes in 1.051036 sec = 97428 kbytes/sec this is right. > Yet we get only a tiny fraction of those (it takes 20 seconds to transfer > 10MB!) when using dd. I also doubt its dd's behavior since how can we explain dd is fine. hardware configuration isn't