From owner-svn-doc-head@FreeBSD.ORG Fri Apr 25 15:26:07 2014 Return-Path: Delivered-To: svn-doc-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id F20F8C00; Fri, 25 Apr 2014 15:26:06 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id DCC581172; Fri, 25 Apr 2014 15:26:06 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s3PFQ6Tk094868; Fri, 25 Apr 2014 15:26:06 GMT (envelope-from dru@svn.freebsd.org) Received: (from dru@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s3PFQ6pX094867; Fri, 25 Apr 2014 15:26:06 GMT (envelope-from dru@svn.freebsd.org) Message-Id: <201404251526.s3PFQ6pX094867@svn.freebsd.org> From: Dru Lavigne Date: Fri, 25 Apr 2014 15:26:06 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r44663 - head/en_US.ISO8859-1/books/handbook/geom X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-head@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: SVN commit messages for the doc tree for head List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Apr 2014 15:26:07 -0000 Author: dru Date: Fri Apr 25 15:26:06 2014 New Revision: 44663 URL: http://svnweb.freebsd.org/changeset/doc/44663 Log: Put RAID3 chapter before Software RAID Devices chapter. Sponsored by: iXsystems Modified: head/en_US.ISO8859-1/books/handbook/geom/chapter.xml Modified: head/en_US.ISO8859-1/books/handbook/geom/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/handbook/geom/chapter.xml Fri Apr 25 14:48:46 2014 (r44662) +++ head/en_US.ISO8859-1/books/handbook/geom/chapter.xml Fri Apr 25 15:26:06 2014 (r44663) @@ -842,6 +842,179 @@ mountroot> + + + + <acronym>RAID</acronym>3 - Byte-level Striping with + Dedicated Parity + + + + + Mark + Gladman + + Written by + + + + + Daniel + Gerzo + + + + + + + + Tom + Rhodes + + Based on documentation by + + + + + Murray + Stokely + + + + + + + GEOM + + + RAID3 + + + RAID3 is a method used to combine several + disk drives into a single volume with a dedicated parity disk. + In a RAID3 system, data is split up into a + number of bytes that are written across all the drives in the + array except for one disk which acts as a dedicated parity disk. + This means that reading 1024KB from a + RAID3 implementation will access all disks in + the array. Performance can be enhanced by using multiple disk + controllers. The RAID3 array provides a + fault tolerance of 1 drive, while providing a capacity of 1 - + 1/n times the total capacity of all drives in the array, where n + is the number of hard drives in the array. Such a configuration + is mostly suitable for storing data of larger sizes such as + multimedia files. + + At least 3 physical hard drives are required to build a + RAID3 array. Each disk must be of the same + size, since I/O requests are interleaved to read or write to + multiple disks in parallel. Also, due to the nature of + RAID3, the number of drives must be + equal to 3, 5, 9, 17, and so on, or 2^n + 1. + + + Creating a Dedicated <acronym>RAID</acronym>3 + Array + + In &os;, support for RAID3 is + implemented by the &man.graid3.8; GEOM + class. Creating a dedicated + RAID3 array on &os; requires the following + steps. + + + While it is theoretically possible to boot from a + RAID3 array on &os;, that configuration + is uncommon and is not advised. + + + + + First, load the geom_raid3.ko + kernel module by issuing the following command: + + &prompt.root; graid3 load + + Alternatively, it is possible to manually load the + geom_raid3.ko module: + + &prompt.root; kldload geom_raid3.ko + + + + Create or ensure that a suitable mount point + exists: + + &prompt.root; mkdir /multimedia/ + + + + Determine the device names for the disks which will be + added to the array, and create the new + RAID3 device. The final device listed + will act as the dedicated parity disk. This + example uses three unpartitioned + ATA drives: + ada1 + and + ada2 + for data, and + ada3 + for parity. + + &prompt.root; graid3 label -v gr0 /dev/ada1 /dev/ada2 /dev/ada3 +Metadata value stored on /dev/ada1. +Metadata value stored on /dev/ada2. +Metadata value stored on /dev/ada3. +Done. + + + + Partition the newly created + gr0 device and put a UFS file + system on it: + + &prompt.root; gpart create -s GPT /dev/raid3/gr0 +&prompt.root; gpart add -t freebsd-ufs /dev/raid3/gr0 +&prompt.root; newfs -j /dev/raid3/gr0p1 + + Many numbers will glide across the screen, and after a + bit of time, the process will be complete. The volume has + been created and is ready to be mounted: + + &prompt.root; mount /dev/raid3/gr0p1 /multimedia/ + + The RAID3 array is now ready to + use. + + + + Additional configuration is needed to retain the above + setup across system reboots. + + + + The geom_raid3.ko module must be + loaded before the array can be mounted. To automatically + load the kernel module during system initialization, add + the following line to + /boot/loader.conf: + + geom_raid3_load="YES" + + + + The following volume information must be added to + /etc/fstab in order to + automatically mount the array's file system during + the system boot process: + + /dev/raid3/gr0p1 /multimedia ufs rw 2 2 + + + + + Software <acronym>RAID</acronym> Devices @@ -1153,179 +1326,6 @@ raid/r0 OPTIMAL ada0 (ACTIVE (ACTIVE)) - - - - <acronym>RAID</acronym>3 - Byte-level Striping with - Dedicated Parity - - - - - Mark - Gladman - - Written by - - - - - Daniel - Gerzo - - - - - - - - Tom - Rhodes - - Based on documentation by - - - - - Murray - Stokely - - - - - - - GEOM - - - RAID3 - - - RAID3 is a method used to combine several - disk drives into a single volume with a dedicated parity disk. - In a RAID3 system, data is split up into a - number of bytes that are written across all the drives in the - array except for one disk which acts as a dedicated parity disk. - This means that reading 1024KB from a - RAID3 implementation will access all disks in - the array. Performance can be enhanced by using multiple disk - controllers. The RAID3 array provides a - fault tolerance of 1 drive, while providing a capacity of 1 - - 1/n times the total capacity of all drives in the array, where n - is the number of hard drives in the array. Such a configuration - is mostly suitable for storing data of larger sizes such as - multimedia files. - - At least 3 physical hard drives are required to build a - RAID3 array. Each disk must be of the same - size, since I/O requests are interleaved to read or write to - multiple disks in parallel. Also, due to the nature of - RAID3, the number of drives must be - equal to 3, 5, 9, 17, and so on, or 2^n + 1. - - - Creating a Dedicated <acronym>RAID</acronym>3 - Array - - In &os;, support for RAID3 is - implemented by the &man.graid3.8; GEOM - class. Creating a dedicated - RAID3 array on &os; requires the following - steps. - - - While it is theoretically possible to boot from a - RAID3 array on &os;, that configuration - is uncommon and is not advised. - - - - - First, load the geom_raid3.ko - kernel module by issuing the following command: - - &prompt.root; graid3 load - - Alternatively, it is possible to manually load the - geom_raid3.ko module: - - &prompt.root; kldload geom_raid3.ko - - - - Create or ensure that a suitable mount point - exists: - - &prompt.root; mkdir /multimedia/ - - - - Determine the device names for the disks which will be - added to the array, and create the new - RAID3 device. The final device listed - will act as the dedicated parity disk. This - example uses three unpartitioned - ATA drives: - ada1 - and - ada2 - for data, and - ada3 - for parity. - - &prompt.root; graid3 label -v gr0 /dev/ada1 /dev/ada2 /dev/ada3 -Metadata value stored on /dev/ada1. -Metadata value stored on /dev/ada2. -Metadata value stored on /dev/ada3. -Done. - - - - Partition the newly created - gr0 device and put a UFS file - system on it: - - &prompt.root; gpart create -s GPT /dev/raid3/gr0 -&prompt.root; gpart add -t freebsd-ufs /dev/raid3/gr0 -&prompt.root; newfs -j /dev/raid3/gr0p1 - - Many numbers will glide across the screen, and after a - bit of time, the process will be complete. The volume has - been created and is ready to be mounted: - - &prompt.root; mount /dev/raid3/gr0p1 /multimedia/ - - The RAID3 array is now ready to - use. - - - - Additional configuration is needed to retain the above - setup across system reboots. - - - - The geom_raid3.ko module must be - loaded before the array can be mounted. To automatically - load the kernel module during system initialization, add - the following line to - /boot/loader.conf: - - geom_raid3_load="YES" - - - - The following volume information must be added to - /etc/fstab in order to - automatically mount the array's file system during - the system boot process: - - /dev/raid3/gr0p1 /multimedia ufs rw 2 2 - - - - - <acronym>GEOM</acronym> Gate Network Devices