From mboxrd@z Thu Jan 1 00:00:00 1970 From: jassduec@gmail.com Subject: RAID 5 throughputs Date: Sat, 19 Aug 2006 11:46:08 -0600 Message-ID: <3a1eedb70608191046o7dd207bfp15f02e90b297b1a9@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline Sender: linux-admin-owner@vger.kernel.org To: linux-admin@vger.kernel.org, linux-config@vger.kernel.org, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org Hi All, I have a storage system with 12 Maxtor 7200 rpm 250GB hard drives in RAID 5 configuration with one hot spare. Maxtor claims that each drive is capable of providing 56 MB/s sustained throughput. My host system is connected to it using 64bit ultra320 Adaptec SCSI card. The host system has 3.0 GHz pentium 4 (with HT) processor and 4 GB of RAM running linux kernel 2.6.9. I was wondering what order of "maximum" sequential read/write, random read/write throughput should i expect using them. I am using some of the benchmarking tools like Bonnie, Bonnie++, tiobench, dd, iometer etc. However the results from them have been very depressing. Theoretically i should be able to achieve a read sequential throughput close to min(10*56 = 560, 320) = 320 MB/s. However my results are no way close to it. I was wondering if anybody can give me some insight of what order of practical throughputs i should expect using linux and what other factors may be creating bottlenecks. TIA