Dual boot with Windows
Windows and Arch Dual Booting:
To start off, you will need to install Windows. The reason to start with windows, is because it will mess with the MBR (Master Boot Record) if it is installed after installing Arch. You then boot up the arch installer. You pretty much do a standard installation, but there are a few things to keep in mind:
1. You will have to use logical partitions for some of our partitions, because there can only be up to 4 primary ones.
2. Very Important, remember to note down your partitions numbers, for IDE drives it is: "hda1, hda2... hda8", SCSI drives: "sda1, sda2... sda8". So note down which type of partitions belong to which partition number. For example:
hda1: Windows hda2: /boot hda3: /root hda4: swap hda5: /home
3. When installing grub, you have to alter the config file that pops up (/boot/grub/menu.lst), and make sure to install grub to /boot (or /root if you did not create a separate partition for /boot). There should be about three lines at the end of the file that speak about chainloading to boot other OSs, these can most generally be simply uncommented if you follow above convention, this would place windows boot point at hd0,0 or sd0,0. Thus you would have something akin to this:
# Windows XP title Windows XP rootnoverify (hd0,0) chainloader +1
The parts of this entry break down as follows:
title Windows XP <<--Can be anything you like, it will just be what is displayed in the grub bootup screen
rootnoverify (hd0,0) <<--Remember the partition numbers we wrote down, here you write in the partition number of your windows partition. This sets the windows boot at root, even though GRUB cannot read it.
chainloader +1 <<-- What this does is call the Windows boot loader that is still in MBR in our case, since GRUB cannot boot Windows itself.
REMEMBER: The file is read from the top and down, so the system listed first, will be the one to auto boot, if no keys are pressed during the grub boot screen.
NOTE:GRUB uses a zero indexed system of numbering drives and partitions, which is a different convention than you may be used to seeing:
First disk, first partition = hda1 = hd0,0 First disk, second partition = hda2 = hd0,1 Second disk, first partition = hdb1 =hd1,0
More information on GRUB configuration can be found in the GRUB manual.
1. Actually you could just use:
hda1 <-WinXP hda2 <-swap hda3 <-/root (Arch) hda4 <-/home (optional)
and not use an extended(logical) partition (as /boot will be in the /root portion as well).
2. LVM (Linux Volume Management) is also a possibility to use, it works fine with arch, you simply create a single LVM partition and let it create the other partitions inside it. This allows a single partition to hold all your needed GNU/Linux stuff, also allows you to easily resize any of them if it becomes necessary.
Notes on /home
You may wish to not store you documents in this mountpoint, especially if you wish to share data between both Windows and Archlinux. Traditionally this was done in a FAT partition because writing to NTFS was still experimental. ntfs-3g now offers stable writing to NTFS partitions, so you can just leave this as another partition that will be shared by both Windows and arch. Another option would be to use some of the tools in Windows, such as fs-driver and use an ext3 or ext2 partition to store documents (although this will be mounted in Windows as ext2 not ext3).
Another option is sort of the reverse of what is described at the beginning of this article where GRUB loads the Windows boot loader, which then loads Windows. Under this option, the Windows boot loader load GRUB, which the loads arch. For information on this method see http://www.geocities.com/epark/linux/grub-w2k-HOWTO.html. I do not believe there are any distinct advantages of this method over the previous one, you will still need a /boot partition, and this one is arguably more difficult to setup.