From owner-freebsd-questions@FreeBSD.ORG Sun Sep 28 10:51:08 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0DC03106569E for ; Sun, 28 Sep 2008 10:51:08 +0000 (UTC) (envelope-from danhdo@gmail.com) Received: from mail-gx0-f17.google.com (mail-gx0-f17.google.com [209.85.217.17]) by mx1.freebsd.org (Postfix) with ESMTP id A10E28FC21 for ; Sun, 28 Sep 2008 10:51:07 +0000 (UTC) (envelope-from danhdo@gmail.com) Received: by gxk10 with SMTP id 10so9557528gxk.19 for ; Sun, 28 Sep 2008 03:51:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:to:subject:date :message-id:mime-version:content-type:x-mailer:thread-index :content-language; bh=/NYhue9wZ2WG91grF36XVm2LbgQHoNz9rw5J5YbEuAw=; b=jNpvO3jY/1ogZEmFyvohz/3N5Cq5VO78XmxwtDu3KpVe9wgnFUakV0qZl2ms9V4nLK QRLlCz6IgEiqU/9x1ATXFLJV9YPCeo/m08GaMRRAKpbuOTgQy24I1kTAO6qV7/9+MjsX YcPOJwlgDhF1xo+zq7i6yVvFKAxdGNVFJg1Vc= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:subject:date:message-id:mime-version:content-type:x-mailer :thread-index:content-language; b=KLGpBviWbWOuEUCK+ipmQysjONXD+dC3T3vxwPIqL7YIr94HCsqVa5Uc2xo6u5WrhM Xynaa4pNY+ao4SwnwVYd/IZVNOtjqx17iqZ/rAsJZQL7uFcggPuZ+RWFvaUBMVnHjq0k YRiO3dOFM5MhMjB5zxcfYuwp5JCtMORSEgDcE= Received: by 10.150.143.5 with SMTP id q5mr5581617ybd.7.1222597537309; Sun, 28 Sep 2008 03:25:37 -0700 (PDT) Received: from Blackhole ([123.20.6.120]) by mx.google.com with ESMTPS id 9sm759015yws.5.2008.09.28.03.25.29 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sun, 28 Sep 2008 03:25:36 -0700 (PDT) From: "Danny Do" To: Date: Sun, 28 Sep 2008 17:24:14 +0700 Message-ID: <00d101c92154$691f53c0$3b5dfb40$@com> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 12.0 thread-index: AckhVFsTHnxF1cNDSkmB38GzEx3A+Q== Content-Language: en-au Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: Hard disk bottle neck. X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Sep 2008 10:51:08 -0000 Hi guys, I have this problem for years but couldn't find a way to solve it. I have a file server handling large files from 1MByte to 1GByte. Server Info: FreeBSD 6.2 Apache 2.2.9 DELL PowerEdge 1850 2GB RAM (only 184MB is active) 6x300MB SCSI 10K RPM RAID5 Gigabit Ethernet Connection My server can output NO MORE than 60Mbps (read only). The bottle neck is the hard disk. If I use ONE connection to download file from my server, the speed can go up to about 400Mbps. If I let visitors download using multiple connections, the server cannot output more than 60Mbps. My service is similar to rapidshare/megaupload, I am wondering how they configure their servers? If I recall correctly, it doesn't cost much time to read the data from the disk but it does cost a lot of time to seek for the data. Correct me if I am wrong, if I increase the read buffer size, there would be less disk seek (disk access). Let's say the read buffer is 64K, if I increase it to 640K, the disk seek would reduce by 90%. Thus, more data can be read from the hard drive. What should I do now? Any suggestion is appreciated! Danny Do