From owner-svn-doc-all@FreeBSD.ORG Wed Mar 5 17:26:02 2014 Return-Path: Delivered-To: svn-doc-all@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 C7874D2B; Wed, 5 Mar 2014 17:26:02 +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)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id A77F73B0; Wed, 5 Mar 2014 17:26:02 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s25HQ2O0010891; Wed, 5 Mar 2014 17:26:02 GMT (envelope-from dru@svn.freebsd.org) Received: (from dru@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s25HQ2nJ010890; Wed, 5 Mar 2014 17:26:02 GMT (envelope-from dru@svn.freebsd.org) Message-Id: <201403051726.s25HQ2nJ010890@svn.freebsd.org> From: Dru Lavigne Date: Wed, 5 Mar 2014 17:26:02 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r44132 - head/en_US.ISO8859-1/books/handbook/advanced-networking X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Mar 2014 17:26:02 -0000 Author: dru Date: Wed Mar 5 17:26:02 2014 New Revision: 44132 URL: http://svnweb.freebsd.org/changeset/doc/44132 Log: Clarify introduction. Sponsored by: iXsystems Modified: head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml Modified: head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml Wed Mar 5 16:29:37 2014 (r44131) +++ head/en_US.ISO8859-1/books/handbook/advanced-networking/chapter.xml Wed Mar 5 17:26:02 2014 (r44132) @@ -3855,146 +3855,62 @@ ifconfig_lagg0="laggp diskless operation - A &os; machine can boot over the network and operate - without a local disk, using file systems mounted from an - NFS server. No system modification is - necessary, beyond standard configuration files. Such a system - is relatively easy to set up because all the necessary elements - are readily available: - - - The &intel; Preboot eXecution Environment - (PXE) can be used to load the kernel over - the network. It provides a form of smart boot - ROM built into some networking cards or - motherboards. See &man.pxeboot.8; for more details. - - - - A sample script - (/usr/share/examples/diskless/clone_root) - eases the creation and maintenance of the workstation's root - file system on the server. The script will probably require - a little customization. - - - - Standard system startup files exist in - /etc to detect and support a diskless - system startup. - - - - Swapping, if needed, can be done either to an - NFS file or to a local disk. - - - - To use PXE when the machine starts, - select the Boot from network option in - the BIOS setup or type a function key - during system initialization. - - There are many ways to set up diskless workstations. Many - elements are involved, and most can be customized to suit local - taste. The following will describe variations on the setup of a - complete system, emphasizing simplicity and compatibility with - the standard &os; startup scripts. The system described has - the following characteristics: - - - - The diskless workstations use a shared, read-only - / and - /usr. - - - - The root file system is a copy of a standard &os; root, - with some configuration files overridden by ones specific to - diskless operation or, possibly, to the workstation they - belong to. - - - - The parts of the root which have to be writable are - overlaid with &man.md.4; file systems. Any changes will be - lost when the system reboots. - - - - - As described, this system is insecure. It should live in - a protected area of a network and be untrusted by other - hosts. - - - - Background Information + (PXE) allows an operating system to boot + over the network. For example, a &os; system can boot over the network and operate + without a local disk, using file systems mounted from an + NFS server. PXE support is usually + available in the BIOS. To use + PXE when the machine starts, + select the Boot from network option in + the BIOS setup or type a function key + during system initialization. - When setting up diskless workstations, several operations - need to be performed for a successful - bootstrap: + In order to provide the files needed for an operating system + to boot over the network, a + PXE setup also requires properly configured + DHCP, TFTP, and NFS + servers, where: - The machine needs to obtain initial parameters such as - its IP address, executable filename, - server name, and root path. This is done using the - DHCP or BOOTP - protocols. DHCP is a compatible - extension of BOOTP, and uses the same - port numbers and basic packet format. It is possible to - configure a system to use only BOOTP - and &man.bootpd.8; is included in the base &os; - system. - - DHCP has a number of advantages - over BOOTP such as nicer configuration - files and support for PXE. This - section describes mainly a DHCP - configuration, with equivalent examples using - &man.bootpd.8; when possible. The sample configuration - uses ISC DHCP which is - available in the Ports Collection. - + Initial parameters, such as an + IP address, executable boot filename and location, + server name, and root path are obtained from the + DHCP server. + - The machine needs to boot the loader using + The operating system loader file is booted using TFTP. - The root filesystem needs to be loaded using + The file systems are loaded using NFS. - - - The possible intermediate bootstrap programs and the - kernel need to be initialized and executed. - PXE loads &man.pxeboot.8;, which is - a modified version of the &os; third stage loader, - &man.loader.8;. The third stage loader will obtain most - parameters necessary to system startup and leave them - in the kernel environment before transferring control. - It is possible to use a GENERIC - kernel in this case. - - - - Finally, the machine needs to access its file systems - using NFS. - - Place tftpboot - anywhere on the server. Make sure that the location is - set in both /etc/inetd.conf and - /usr/local/etc/dhcpd.conf. + When a computer PXE boots, it receives information over + DHCP about where to obtain the initial boot + loader file. After the host computer + receives this information, it downloads the boot loader via + TFTP and then executes the boot loader. + In &os;, the boot loader file is + /boot/pxeboot. After + /boot/pxeboot executes, the &os; kernel is + loaded and the rest of the &os; bootup sequence proceeds, as described in + . - Refer to &man.diskless.8; for more information. - + This section describes how to configure these services + on a &os; system so that other systems can + PXE boot into &os;. Refer to &man.diskless.8; for more information. + + + As described, the system providing these services is insecure. It should live in + a protected area of a network and be untrusted by other + hosts. + @@ -4015,32 +3931,6 @@ ifconfig_lagg0="laggp - The &intel; Preboot eXecution Environment - (PXE) allows booting the operating system - over the network. PXE support is usually - provided in the BIOS where it can be enabled - in the BIOS settings which enable booting - from the network. A fully functioning - PXE setup also requires properly configured - DHCP and TFTP - servers. - - When the host computer boots, it receives information over - DHCP about where to obtain the initial boot - loader via TFTP. After the host computer - receives this information, it downloads the boot loader via - TFTP and then executes the boot loader. - This is documented in section 2.2.1 of the Preboot - Execution Environment (PXE) - Specification. In &os;, the boot loader retrieved - during the PXE process is - /boot/pxeboot. After - /boot/pxeboot executes, the &os; kernel is - loaded and the rest of the &os; bootup sequence proceeds. - Refer to for more information about the - &os; booting process. - Choose a directory which will have a &os; @@ -4051,6 +3941,11 @@ ifconfig_lagg0="laggp &prompt.root; export NFSROOTDIR=/b/tftpboot/FreeBSD/install &prompt.root; mkdir -p ${NFSROOTDIR} + + Place tftpboot + anywhere on the server. Make sure that the location is + set in both /etc/inetd.conf and + /usr/local/etc/dhcpd.conf.