<!DOCTYPE RefEntry PUBLIC "-//OASIS//DTD DocBook V4.1//EN"><refentry id="sdisklabel"><refmeta><refentrytitle>sdisklabel</refentrytitle><manvolnum>8</manvolnum><refmiscinfo>sdisklabel</refmiscinfo></refmeta><refnamediv><refname>sdisklabel</refname><refpurpose>Create/modify disklabels on Linux/Alpha systems</refpurpose></refnamediv><refsect1><title>SYNOPSIS</title><para>sdisklabel <parameter>drive [print|zero|sum]</parameter></para><para>sdisklabel <parameter>drive size partsize</parameter></para><para>sdisklabel <parameter>drive partnum offset size parttype</parameter></para><!-- <para>sdisklabel <parameter>drive size size_in_sectors</parameter></para><para>sdisklabel <parameter>drive partition_number offset_in_sectors size_in_sectors partition_type</parameter></para> --></refsect1> <!-- <refsect1><title>COPYRIGHT</title><para><application>sdisklabel</application> is Copyright (C) </para></refsect1> --><refsect1><title>DESCRIPTIONS</title><para><indexterm><primary>sdisklabel</primary></indexterm><application>sdisklabel</application>can be used to create partitions (called disklabels) on Linux/Alphasystems. You <emphasis>must</emphasis> use disklabels instead of the<productname>DOS</productname> typepartitioning scheme on any hard disk which you want to boot from via SRM orwhich you want to share with <productname>HP Tru64</productname>.If you instead are booting from <application>milo</application>then you <emphasis>must not</emphasis> use disklabels on your boot hard disk.</para><para>Even if you are using disklabels, it is recommended to use <application>fdisk</application>(8) insteadof <application>sdisklabel</application>.</para><para><application>sdisklabel</application> also assumes you have a SCSI disk with 512-byte sectors,though it should work fine on an IDE drive as well.  All sizes arespecified on the command line in sectors.</para><para>There are 8 partitions in total which are numbered from 0 to 7. Theycorrespond to BSD disklabels A to H.Partitions have to be added sequentially, as <application>sdisklabel</application> won't letyou leave empty partitions unlike many BSD disklabel programs. If youwant this (or if you want overlapping disk labels) use <application>fdisk</application>(8) instead.</para><para>First off, if you have an invalid disk label (you've never run <application>sdisklabel</application> on this diskbefore) you have to issue</para><para><command>sdisklabel <parameter>/dev/sda zero</parameter></command></para><para>(<filename>/dev/sda</filename> is the device you're partitioning, substitute as appropriate).</para><para>This zeros out your disk label. Only do this if you really want tozero your disk label. It just does it; it doesn't ask, or warn, oranything.</para><para>The program also probably printed out the size of your disk in Kb. Ifit was wrong, you now get to use the "<parameter>size xxx</parameter>"option along with therest of these commands. The size isn't critical, it's just used to tryand make sure you don't go past the end of the disk.</para><para>Next, add your first partition. This <emphasis>doesn't</emphasis>start from 0, as youhave to leave room for the boot loader and other stuff. 256K (or 512sectors) will be enough.</para><para>Let's pretend that you want to make a 250000 Kb partition startingfrom sector offset 512:</para><para><command>sdisklabel <parameter>/dev/sda 0 512 500000 8 print</parameter></command></para><para>The last number is the filesystem type, and is currently 8 for ext2fsfilesystems. (A different number would be used to specify an<productname>Tru64</productname>partition, for example).</para><para>If all was successful, the program should print out the partition (thelast keyword, "print", specifies that it should print the partitionafter modifying it with the previous command), and you should seesomething like</para><para><blockquote><literallayout>----------------------------------------------------------I think your disk is 528870K total size.If I'm wrong, override the size with the 'size num' optionpartition 0: type 8, starts sector 512, size 500000----------------------------------------------------------</literallayout></blockquote></para><para>You can then add the next partition, which would be partition 1.To add a second partition that is 200000 Kb long, you'd run</para><para><command>sdisklabel <parameter>/dev/sda 1 512256 400000 8 print</parameter></command></para><para>And both partitions would then be printed out.</para><para>If for some reason the size got determined incorrectly, you'd doinstead</para><para><command>sdisklabel <parameter>/dev/sda size 528870 0 512 400000 8 print</parameter></command></para><para>The size option should come immediately after the device name, and thesize is the total # of sectors on the drive.</para></refsect1><refsect1><title>BUGS</title><para><application>sdisklabel</application> does not check for all errors, souse with care.</para></refsect1><refsect1><title>NOTES</title><para>If you want to share the disk with <productname>HP Tru64</productname>(<productname>OSF/1</productname>) it is recommended touse the <productname>Tru64</productname> partitioning tools to prepare the disk.</para><para>To actually boot from the freshly labeled disk you also need to installa boot strap as well, see<application>aboot</application>(8) and <application>swriteboot</application>(8)for details.</para><para>The print command may be placed before or after any other command.</para><para>In case you do want to leave empty partitions or create lables wichextend beyond the end of the disk (e.g. when you know <application>sdisklabel</application> is reporting a wrong size) thenuse can use the <parameter>force</parameter> switch on the command line.</para></refsect1><refsect1><title>AUTHOR</title><para>This man page was written by Helge Kreutzmann <email>kreutzm@itp.uni-hannover.de</email> for the Debian GNU/Linux project but may be used by others. It isheavily based on the <filename>README</filename> provided along with the<application>sdisklabel</application> source.</para></refsect1><refsect1><title>SEE ALSO</title><para> <application>fdisk</application>(8), <application>aboot</application>(8), <application>swriteboot</application>(8)</para></refsect1></refentry>