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diff --git a/en_US.ISO8859-1/articles/multi-os/article.sgml b/en_US.ISO8859-1/articles/multi-os/article.sgml deleted file mode 100644 index 926303aec2..0000000000 --- a/en_US.ISO8859-1/articles/multi-os/article.sgml +++ /dev/null @@ -1,752 +0,0 @@ -<!-- $FreeBSD$ --> - -<!DOCTYPE ARTICLE PUBLIC "-//FreeBSD//DTD DocBook V4.1-Based Extension//EN" [ -<!ENTITY % articles.ent PUBLIC "-//FreeBSD//ENTITIES DocBook FreeBSD Articles Entity Set//EN"> -%articles.ent; -]> - -<article> - <articleinfo> - <title>Installing and Using FreeBSD With Other Operating Systems</title> - - <authorgroup> - <author> - <firstname>Jay</firstname> - - <surname>Richmond</surname> - - <affiliation> - <address> - <email>jayrich@sysc.com</email> - </address> - </affiliation> - </author> - </authorgroup> - - <pubdate>6 August 1996</pubdate> - - <legalnotice id="trademarks" role="trademarks"> - &tm-attrib.freebsd; - &tm-attrib.ibm; - &tm-attrib.linux; - &tm-attrib.microsoft; - &tm-attrib.powerquest; - &tm-attrib.general; - </legalnotice> - - <abstract> - <para>This document discusses how to make FreeBSD coexist nicely - with other popular operating systems such as Linux, &ms-dos;, - &os2;, and &windows; 95. Special thanks to: Annelise Anderson - <email>andrsn@stanford.edu</email>, Randall Hopper - <email>rhh@ct.picker.com</email>, and &a.jkh;.</para> - </abstract> - </articleinfo> - - <sect1> - <title>Overview</title> - - <para>Most people can not fit these operating systems together - comfortably without having a larger hard disk, so special - information on large EIDE drives is included. Because there are - so many combinations of possible operating systems and hard disk - configurations, the <xref linkend="ch5"> section may be of the - most use to you. It contains descriptions of specific working - computer setups that use multiple operating systems.</para> - - <para>This document assumes that you have already made room on - your hard disk for an additional operating system. Any time you - repartition your hard drive, you run the risk of destroying the - data on the original partitions. However, if your hard drive is - completely occupied by DOS, you might find the FIPS utility - (included on the FreeBSD CDROM in the - <filename>\TOOLS</filename> directory or via <ulink - url="ftp://ftp.FreeBSD.org/pub/FreeBSD/tools/">ftp</ulink>) - useful. It lets you repartition your hard disk without - destroying the data already on it. There is also a commercial - program available called <application>&partitionmagic;</application>, which lets you size - and delete partitions without consequence.</para> - </sect1> - - <sect1 id="ch2"> - <title>Overview of Boot Managers</title> - - <para>These are just brief descriptions of some of the different - boot managers you may encounter. Depending on your computer - setup, you may find it useful to use more than one of them on - the same system.</para> - - <variablelist> - <varlistentry> - <term>Boot Easy</term> - - <listitem> - <para>This is the default boot manager used with FreeBSD. - It has the ability to boot most anything, including BSD, - &os2; (HPFS), &windows; 95 (FAT and FAT32), and Linux. - Partitions are selected with the function keys.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>&os2; Boot Manager</term> - - <listitem> - <para>This will boot FAT, FAT32, HPFS, FFS (FreeBSD), and EXT2 - (Linux). Partitions - are selected using arrow keys. The &os2; Boot Manager is - the only one to use its own separate partition, unlike the - others which use the master boot record (MBR). Therefore, - it must be installed below the 1024th cylinder to avoid - booting problems. It can boot Linux using LILO when it is - part of the boot sector, not the MBR. Go to <ulink - url="http://www.linuxresources.com/LDP/HOWTO/HOWTO-INDEX.html">Linux - HOWTOs</ulink> on the World Wide Web for more - information on booting Linux with the &os2; boot - manager.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>OS-BS</term> - - <listitem> - <para>This is an alternative to Boot Easy. It gives you more - control over the booting process, with the ability to set - the default partition to boot and the booting timeout. - The beta version of this programs allows you to boot by - selecting the OS with your arrow keys. It is included on - the FreeBSD CD in the <filename class="directory">\TOOLS</filename> - directory, and via <ulink - url="ftp://ftp.FreeBSD.org/pub/FreeBSD/tools/">ftp</ulink>.</para> - </listitem> - </varlistentry> - - <varlistentry> - <term>LILO, or LInux LOader</term> - - <listitem> - <para>This is a limited boot manager. It will boot FreeBSD, - though some customization work is required in the LILO - configuration file.</para> - </listitem> - </varlistentry> - </variablelist> - - <note id="fat32"> - <title>About FAT32</title> - - <para>FAT32 is the replacement to the FAT filesystem included in - Microsoft's OEM SR2 Beta release, which started replacing FAT - on computers pre-loaded with &windows; 95 towards the - end of 1996. It converts the normal FAT filesystem and - allows you to use smaller cluster sizes for larger hard - drives. FAT32 also modifies the traditional FAT boot sector - and allocation table, making it incompatible with some boot - managers.</para> - </note> - </sect1> - - <sect1 id="ch3"> - <title>A Typical Installation</title> - - <para>Let's say I have two large EIDE hard drives, and I want to - install FreeBSD, Linux, and &windows; 95 on them.</para> - - <para>Here is how I might do it using these hard disks:</para> - - <itemizedlist> - <listitem> - <para><filename>/dev/wd0</filename> (first physical hard disk)</para> - </listitem> - - <listitem> - <para><filename>/dev/wd1</filename> (second hard disk)</para> - </listitem> - </itemizedlist> - - <para>Both disks have 1416 cylinders.</para> - - <procedure> - <step> - <para>I boot from a &ms-dos; or &windows; 95 boot disk that - contains the <filename>FDISK.EXE</filename> utility and make a small - 50 MB primary partition (35-40 for &windows; 95, plus a - little breathing room) on the first disk. Also create a - larger partition on the second hard disk for my &windows; - applications and data.</para> - </step> - - <step> - <para>I reboot and install &windows; 95 (easier said than done) - on the <filename>C:</filename> partition.</para> - </step> - - <step> - <para>The next thing I do is install Linux. I am not sure - about all the distributions of Linux, but <ulink url="http://www.slackware.com">Slackware</ulink> includes - LILO (see <xref linkend="ch2">). When I am partitioning out - my hard disk with Linux <command>fdisk</command>, I would - put all of Linux on the first drive (maybe 300 MB for a - nice root partition and some swap space).</para> - </step> - - <step> - <para>After I install Linux, and are prompted about installing - LILO, make <emphasis>sure</emphasis> that I install it on the boot sector of my - root Linux partition, not in the MBR (master boot - record).</para> - </step> - - <step> - <para>The remaining hard disk space can go to FreeBSD. I also - make sure that my FreeBSD root slice does not go beyond the - 1024th cylinder. (The 1024th cylinder is 528 MB into the - disk with our hypothetical 720 MB disks). I will use the - rest of the hard drive (about 270 MB) for the - <filename class="directory">/usr</filename> and <filename class="directory">/</filename> slices if I wish. The - rest of the second hard disk (size depends on the amount of - my &windows; application/data partition that I created in step - 1) can go to the <filename class="directory">/usr/src</filename> slice and swap - space.</para> - </step> - - <step> - <para>When viewed with the &windows; 95 <command>fdisk</command> - utility, my hard drives should now look something like this: - - <screen>--------------------------------------------------------------------- - - Display Partition Information - -Current fixed disk drive: 1 - -Partition Status Type Volume_Label Mbytes System Usage -C: 1 A PRI DOS 50 FAT** 7% - 2 A Non-DOS (Linux) 300 43% - -Total disk space is 696 Mbytes (1 Mbyte = 1048576 bytes) - -Press Esc to continue - ---------------------------------------------------------------------- - - Display Partition Information - -Current fixed disk drive: 2 - -Partition Status Type Volume_Label Mbytes System Usage -D: 1 A PRI DOS 420 FAT** 60% - -Total disk space is 696 Mbytes (1 Mbyte = 1048576 bytes) - -Press Esc to continue - ----------------------------------------------------------------------</screen> - ** May say FAT16 or FAT32 if you are using the OEM SR2 - update. See <xref linkend="ch2">.</para> - </step> - - <step> - <para>Install FreeBSD. I make sure to boot with my first hard - disk set at <quote>NORMAL</quote> in the BIOS. If it is not, - I will have the enter my true disk geometry at boot time (to - get this, boot &windows; 95 and consult Microsoft Diagnostics - (<filename>MSD.EXE</filename>), or check your BIOS) with the - parameter <literal>hd0=1416,16,63</literal> where - <replaceable>1416</replaceable> is the number of cylinders on my hard - disk, <replaceable>16</replaceable> is the number of heads per track, - and <replaceable>63</replaceable> is the number of sectors per track on - the drive.</para> - </step> - - <step> - <para>When partitioning out the hard disk, I make sure to - install Boot Easy on the first disk. I do not worry about - the second disk, nothing is booting off of it.</para> - </step> - - <step> - <para>When I reboot, Boot Easy should recognize my three - bootable partitions as DOS (&windows; 95), Linux, and BSD - (FreeBSD).</para> - </step> - </procedure> - </sect1> - - <sect1 id="ch4"> - <title>Special Considerations</title> - - <para>Most operating systems are very picky about where and how - they are placed on the hard disk. &windows; 95 and DOS need to be - on the first primary partition on the first hard disk. &os2; is - the exception. It can be installed on the first or second disk - in a primary or extended partition. If you are not sure, keep - the beginning of the bootable partitions below the 1024th - cylinder.</para> - - <para>If you install &windows; 95 on an existing BSD system, it will - <quote>destroy</quote> the MBR, and you will have to reinstall your - previous boot manager. Boot Easy can be reinstalled by using - the <filename>BOOTINST.EXE</filename> utility included in the <filename class="directory">\TOOLS</filename> directory on the - CDROM, and via <ulink - url="ftp://ftp.FreeBSD.org/pub/FreeBSD/tools/">ftp</ulink>. - You can also re-start the installation process and go to the - partition editor. From there, mark the FreeBSD partition as - bootable, select Boot Manager, and then type W to (W)rite out - the information to the MBR. You can now reboot, and Boot Easy - should then recognize &windows; 95 as DOS.</para> - - <para>Please keep in mind that &os2; can read FAT and HPFS - partitions, but not FFS (FreeBSD) or EXT2 (Linux) partitions. - Likewise, &windows; 95 can only read and write to FAT and FAT32 - (see <xref linkend="ch2">) partitions. FreeBSD can read most - filesystems, but currently cannot read HPFS partitions. Linux - can read HPFS partitions, but can not write to them. Recent - versions of the Linux kernel (2.x) can read and write to &windows; - 95 VFAT partitions (VFAT is what gives &windows; 95 long file - names - it is pretty much the same as FAT). Linux can read and - write to most filesystems. Got that? I hope so.</para> - </sect1> - - <sect1 id="ch5"> - <title>Examples</title> - - <para><emphasis>(section needs work, please send your example to - <email>jayrich@sysc.com</email>)</emphasis>.</para> - - <para>FreeBSD + &windows; 95: If you installed FreeBSD after &windows; 95, - you should see <literal>DOS</literal> on the Boot Easy menu. This is - &windows; 95. If you installed &windows; 95 after FreeBSD, read - <xref linkend="ch4"> above. As long as your hard disk does not - have 1024 cylinders you should not have a problem booting. If - one of your partitions goes beyond the 1024th cylinder however, - and you get messages like <errorname>invalid system disk</errorname> - under DOS (&windows; 95) and FreeBSD will not boot, try looking - for a setting in your BIOS called <quote>> 1024 cylinder - support</quote> or <quote>NORMAL/LBA</quote> mode. DOS may need LBA - (Logical Block Addressing) in order to boot correctly. If the - idea of switching BIOS settings every time you boot up does not - appeal to you, you can boot FreeBSD through DOS via the - <filename>FBSDBOOT.EXE</filename> utility on the CD (It should find your - FreeBSD partition and boot it.)</para> - - <para>FreeBSD + &os2; + &windows; 95: Nothing new here. The &os2; boot manager - can boot all of these operating systems, so that should not be a - problem.</para> - - <para>FreeBSD + Linux: You can also use Boot Easy to boot both - operating systems.</para> - - <para>FreeBSD + Linux + &windows; 95: (see <xref linkend="ch3">)</para> - </sect1> - - <sect1 id="sources"> - <title>Other Sources of Help</title> - - <para>There are many <ulink - url="http://www.linuxresources.com/LDP/HOWTO/HOWTO-INDEX.html">Linux - HOW-TOs</ulink> that deal with multiple operating systems on - the same hard disk.</para> - - <para>The <ulink - url="http://www.linuxresources.com/LDP/HOWTO/mini/Linux+DOS+Win95+OS2.html">Linux+DOS+Win95+OS2 - mini-HOWTO</ulink> offers help on configuring the &os2; boot - manager, and the <ulink - url="http://www.linuxresources.com/LDP/HOWTO/mini/Linux+FreeBSD.html">Linux+FreeBSD - mini-HOWTO</ulink> might be interesting as well. The <ulink - url="http://www.in.net/~jkatz/win95/Linux-HOWTO.html">Linux-HOWTO</ulink> - is also helpful.</para> - - <para>The <ulink - url="http://www.tburke.net/info/ntldr/ntldr_hacking_guide.htm">&windowsnt; - Loader Hacking Guide</ulink> provides good information on - multibooting &windowsnt;, &windows; 95, and DOS with other operating - systems.</para> - - <para>And Hale Landis's <quote>How It Works</quote> document pack contains some - good info on all sorts of disk geometry and booting related - topics. You can find it at - <ulink url="ftp://fission.dt.wdc.com/pub/otherdocs/pc_systems/how_it_works/allhiw.zip"></ulink>.</para> - - <para>Finally, do not overlook FreeBSD's kernel documentation on - the booting procedure, available in the kernel source - distribution (it unpacks to <ulink - url="file://localhost/usr/src/sys/i386/boot/biosboot/README.386BSD">/usr/src/sys/i386/boot/biosboot/README.386BSD</ulink>.</para> - </sect1> - - <sect1> - <title>Technical Details</title> - - <para><emphasis>(Contributed by Randall Hopper, - <email>rhh@ct.picker.com</email>)</emphasis></para> - - <para>This section attempts to give you enough basic information - about your hard disks and the disk booting process so that you - can troubleshoot most problems you might encounter when getting - set up to boot several operating systems. It starts in pretty - basic terms, so you may want to skim down in this section until - it begins to look unfamiliar and then start reading.</para> - - <sect2> - <title>Disk Primer</title> - - <para>Three fundamental terms are used to describe the location - of data on your hard disk: Cylinders, Heads, and Sectors. - It is not particularly important to know what these terms - relate to except to know that, together, they identify where - data is physically on your disk.</para> - - <para>Your disk has a particular number of cylinders, number of - heads, and number of sectors per cylinder-head (a - cylinder-head also known now as a track). Collectively this - information defines the <quote>physical disk geometry</quote> for your hard - disk. There are typically 512 bytes per sector, and 63 - sectors per track, with the number of cylinders and heads - varying widely from disk to disk. Thus you can figure the - number of bytes of data that will fit on your own disk by - calculating:</para> - - <informalexample> - <para>(# of cylinders) × (# heads) × (63 - sectors/track) × (512 bytes/sect)</para> - </informalexample> - - <para>For example, on my 1.6 Gig Western Digital AC31600 EIDE hard - disk, that is:</para> - - <informalexample> - <para>(3148 cyl) × (16 heads) × (63 - sectors/track) × (512 bytes/sect)</para> - </informalexample> - - <para>which is 1,624,670,208 bytes, or around 1.6 Gig.</para> - - <para>You can find out the physical disk geometry (number of - cylinders, heads, and sectors/track counts) for your hard - disks using ATAID or other programs off the net. Your hard - disk probably came with this information as well. Be careful - though: if you are using BIOS LBA (see <xref - linkend="limits">), you can not use just any program to get - the physical geometry. This is because many programs (e.g. - <filename>MSD.EXE</filename> or FreeBSD fdisk) do not identify the - physical disk geometry; they instead report the - <firstterm>translated geometry</firstterm> (virtual numbers from using - LBA). Stay tuned for what that means.</para> - - <para>One other useful thing about these terms. Given 3 - numbers—a cylinder number, a head number, and a - sector-within-track number—you identify a specific - absolute sector (a 512 byte block of data) on your disk. - Cylinders and Heads are numbered up from 0, and Sectors are - numbered up from 1.</para> - - <para>For those that are interested in more technical details, - information on disk geometry, boot sectors, BIOSes, etc. can - be found all over the net. Query Lycos, Yahoo, etc. for - <literal>boot sector</literal> or <literal>master boot record</literal>. - Among the useful info you will find are Hale Landis's - <citetitle>How It Works</citetitle> document pack. See the <xref - linkend="sources"> section for a few pointers to this - pack.</para> - - <para>Ok, enough terminology. We are talking about booting - here.</para> - </sect2> - - <sect2 id="booting"> - <title>The Booting Process</title> - - <para>On the first sector of your disk (Cyl 0, Head 0, Sector 1) - lives the Master Boot Record (MBR). It contains a map of your - disk. It identifies up to 4 <firstterm>partitions</firstterm>, each of - which is a contiguous chunk of that disk. FreeBSD calls - partitions <firstterm>slices</firstterm> to avoid confusion with its - own partitions, but we will not do that here. Each partition can - contain its own operating system.</para> - - <para>Each partition entry in the MBR has a <firstterm>Partition - ID</firstterm>, a <firstterm>Start Cylinder/Head/Sector</firstterm>, and an - <firstterm>End Cylinder/Head/Sector</firstterm>. The Partition ID - tells what type of partition it is (what OS) and the Start/End - tells where it is. <xref linkend="tbl-pid"> lists a - smattering of some common Partition IDs.</para> - - <table id="tbl-pid"> - <title>Partition IDs</title> - - <tgroup cols="2"> - <thead> - <row> - <entry>ID (hex)</entry> - <entry>Description</entry> - </row> - </thead> - - <tbody> - <row> - <entry>01</entry> - <entry>Primary DOS12 (12-bit FAT)</entry> - </row> - - <row> - <entry>04</entry> - <entry>Primary DOS16 (16-bit FAT)</entry> - </row> - - <row> - <entry>05</entry> - <entry>Extended DOS</entry> - </row> - - <row> - <entry>06</entry> - <entry>Primary big DOS (> 32MB)</entry> - </row> - - <row> - <entry>0A</entry> - <entry>&os2;</entry> - </row> - - <row> - <entry>83</entry> - <entry>Linux (EXT2FS)</entry> - </row> - - <row> - <entry>A5</entry> - <entry>FreeBSD, NetBSD, 386BSD (UFS)</entry> - </row> - </tbody> - </tgroup> - </table> - - <para>Note that not all partitions are bootable (e.g. Extended - DOS). Some are—some are not. What makes a partition - bootable is the configuration of the <firstterm>Partition Boot - Sector</firstterm> that exists at the beginning of each - partition.</para> - - <para>When you configure your favorite boot manager, it looks up - the entries in the MBR partition tables of all your hard disks - and lets you name the entries in that list. Then when you - boot, the boot manager is invoked by special code in the - Master Boot Sector of the first probed hard disk on your - system. It looks at the MBR partition table entry - corresponding to the partition choice you made, uses the Start - Cylinder/Head/Sector information for that partition, loads up - the Partition Boot Sector for that partition, and gives it - control. That Boot Sector for the partition itself contains - enough information to start loading the operating system on - that partition.</para> - - <para>One thing we just brushed past that is important to know. - All of your hard disks have MBRs. However, the one that is - important is the one on the disk that is first probed by the - BIOS. If you have only IDE hard disks, it is the first IDE disk - (e.g. primary disk on first controller). Similarly for SCSI - only systems. If you have both IDE and SCSI hard disks - though, the IDE disk is typically probed first by the BIOS, so - the first IDE disk is the first probed disk. The boot manager - you will install will be hooked into the MBR on this first - probed hard disk that we have just described.</para> - </sect2> - - <sect2 id="limits"> - <title>Booting Limitations and Warnings</title> - - <para>Now the interesting stuff that you need to watch out - for.</para> - - <sect3> - <title>The dreaded 1024 cylinder limit and how BIOS LBA helps</title> - - <para>The first part of the booting process is all done - through the BIOS, (if that is a new term to you, the BIOS is - a software chip on your system motherboard which provides - startup code for your computer). As such, this first part - of the process is subject to the limitations of the BIOS - interface.</para> - - <para>The BIOS interface used to read the hard disk during - this period (INT 13H, Subfunction 2) allocates 10 bits to - the Cylinder Number, 8 bits to the Head Number, and 6 bits - to the Sector Number. This restricts users of this - interface (i.e. boot managers hooked into your disk's MBR as - well as OS loaders hooked into the Boot Sectors) to the - following limits:</para> - - <itemizedlist> - <listitem> - <para>1024 cylinders, max</para> - </listitem> - - <listitem> - <para>256 heads, max</para> - </listitem> - - <listitem> - <para>64 sectors/track, max (actually 63, <literal>0</literal> - is not available)</para> - </listitem> - </itemizedlist> - - <para>Now big hard disks have lots of cylinders but not a lot - of heads, so invariably with big hard disks the number of - cylinders is greater than 1024. Given this and the BIOS - interface as is, you can not boot off just anywhere on your - hard disk. The boot code (the boot manager and the OS - loader hooked into all bootable partitions' Boot Sectors) - has to reside below cylinder 1024. In fact, if your hard - disk is typical and has 16 heads, this equates to:</para> - - <informalexample> - <para>1024 cyl/disk × 16 heads/disk × 63 - sect/(cyl-head) × 512 bytes/sector</para> - </informalexample> - - <para>which is around the often-mentioned 528MB limit.</para> - - <para>This is where BIOS LBA (Logical Block Addressing) comes - in. BIOS LBA gives the user of the BIOS API calls access to - physical cylinders above 1024 though the BIOS interfaces by - redefining a cylinder. That is, it remaps your cylinders - and heads, making it appear through the BIOS as though the - disk has fewer cylinders and more heads than it actually - does. In other words, it takes advantage of the fact that - hard disks have relatively few heads and lots of cylinders - by shifting the balance between number of cylinders and - number of heads so that both numbers lie below the - above-mentioned limits (1024 cylinders, 256 heads).</para> - - <para>With BIOS LBA, the hard disk size limitation is - virtually removed (well, pushed up to 8 Gigabytes anyway). - If you have an LBA BIOS, you can put FreeBSD or any OS - anywhere you want and not hit the 1024 cylinder - limit.</para> - - <para>To use my 1.6 Gig Western Digital as an example again, - its physical geometry is:</para> - - <informalexample> - <para>(3148 cyl, 16 heads, 63 sectors/track, 512 - bytes/sector)</para> - </informalexample> - - <para>However, my BIOS LBA remaps this to:</para> - - <informalexample> - <para>(787 cyl, 64 heads, 63 sectors/track, 512 - bytes/sector)</para> - </informalexample> - - <para>giving the same effective size disk, but with cylinder - and head counts within the BIOS API's range (Incidentally, I - have both Linux and FreeBSD existing on one of my hard disks - above the 1024th physical cylinder, and both operating - systems boot fine, thanks to BIOS LBA).</para> - </sect3> - - <sect3> - <title>Boot Managers and Disk Allocation</title> - - <para>Another gotcha to watch out when installing boot - managers is allocating space for your boot manager. It is - best to be aware of this issue up front to save yourself - from having to reinstall one or more of your OSs.</para> - - <para>If you followed the discussion in <xref - linkend="booting"> about the Master Boot Sector (where the - MBR is), Partition Boot Sectors, and the booting process, - you may have been wondering just exactly where on your hard - disk that nifty boot manager is going to live. Well, some - boot managers are small enough to fit entirely within the - Master Boot Sector (Cylinder 0, Head 0, Sector 0) along with - the partition table. Others need a bit more room and - actually extend a few sectors past the Master Boot Sector in - the Cylinder 0 Head 0 track, since that is typically - free…typically.</para> - - <para>That is the catch. Some operating systems (FreeBSD - included) let you start their partitions right after the - Master Boot Sector at Cylinder 0, Head 0, Sector 2 if you - want. In fact, if you give FreeBSD's sysinstall a disk with - an empty chunk up front or the whole disk empty, that is - where it will start the FreeBSD partition by default (at least - it did when I fell into this trap). Then when you go to - install your boot manager, if it is one that occupies a few - extra sectors after the MBR, it will overwrite the front of - the first partition's data. In the case of FreeBSD, this - overwrites the disk label, and renders your FreeBSD - partition unbootable.</para> - - <para>The easy way to avoid this problem (and leave yourself - the flexibility to try different boot managers later) is - just to always leave the first full track on your disk - unallocated when you partition your disk. That is, leave - the space from Cylinder 0, Head 0, Sector 2 through Cylinder - 0, Head 0, Sector 63 unallocated, and start your first - partition at Cylinder 0, Head 1, Sector 1. For what it is - worth, when you create a DOS partition at the front of your - disk, DOS leaves this space open by default (this is why - some boot managers assume it is free). So creating a DOS - partition up at the front of your disk avoids this problem - altogether. I like to do this myself, creating 1 Meg DOS - partition up front, because it also avoids my primary DOS - drive letters shifting later when I repartition.</para> - - <para>For reference, the following boot managers use the - Master Boot Sector to store their code and data:</para> - - <itemizedlist> - <listitem> - <para>OS-BS 1.35</para> - </listitem> - - <listitem> - <para>Boot Easy</para> - </listitem> - - <listitem> - <para>LILO</para> - </listitem> - </itemizedlist> - - <para>These boot managers use a few additional sectors after - the Master Boot Sector:</para> - - <itemizedlist> - <listitem> - <para>OS-BS 2.0 Beta 8 (sectors 2-5)</para> - </listitem> - - <listitem> - <para>The &os2; boot manager</para> - </listitem> - </itemizedlist> - </sect3> - - <sect3> - <title>What if your machine will not boot?</title> - - <para>At some point when installing boot managers, you might - leave the MBR in a state such that your machine will not boot. - This is unlikely, but possible when re-FDISKing underneath - an already-installed boot manager.</para> - - <para>If you have a bootable DOS partition on your disk, you - can boot off a DOS floppy, and run:</para> - - <informalexample> - <screen>A:\> <userinput>FDISK /MBR</userinput></screen> - </informalexample> - - <para>to put the original, simple DOS boot code back into the - system. You can then boot DOS (and DOS only) off the hard - drive. Alternatively, just re-run your boot manager - installation program off a bootable floppy.</para> - </sect3> - </sect2> - </sect1> -</article> |