Dual boot with Windows

From ArchWiki
Revision as of 19:37, 9 September 2012 by DSpider (talk | contribs) (marked as out of date)
Jump to: navigation, search

This is a simple article detailing different methods of Arch/Windows coexistence.

Tango-view-refresh-red.pngThis article or section is out of date.Tango-view-refresh-red.png

Reason: GRUB Legacy support has been dropped from Arch Linux:
http://www.archlinux.org/news/grub-legacy-no-longer-supported/ (Discuss in Talk:Dual boot with Windows#)

Windows and Arch Dual Booting

In this example, we will install Windows first, and subsequently install the GRUB bootloader along with Arch, allowing for dual boot.

Installation will be standard, but there are a few things to keep in mind:

1. You may have to use logical partitions for some of your partitions, because there can only be up to 4 primary partitions per disk.

2. Remember to write down your partitions numbers: "sda1, sda2... sda8", noting which type of partitions belong to their relevant number. For example:

Windows - 30 GB should be enough. Many new games exceed 10GB each so bear this in mind.
/boot - 100 MB is enough (optional)
/ - 10 GB should be enough. If you're planning on using KDE or installing a bunch of games, you may wish to allocate more; perhaps 15 GB.
swap - between 1024 MB and 4096 MB (optional). With 2 GB+ RAM you may even wish to skip it entirely. If you're only using swap for hibernation, you can also use a swapfile, which will free up one of those 4 primary partitions.
/home - rest of the drive (optional)
Note: Older motherboards have a 1024 cylinder limit. This means that the BIOS cannot access things beyond the 1024th cylinder (about 8.5 GB), so the /boot partition should be in the first 8.5 GB (most likely before the Windows partition). GParted Live, Parted Magic or SystemRescueCd are useful for moving and resizing partitions to accommodate this.

3. When installing GRUB, you must configure /boot/grub/menu.lst), and make sure to install GRUB to /boot (or root (/) if you did not create a separate partition for /boot). Installing GRUB onto your Windows partition may cause Windows not to 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 uncommented if you follow above convention, this would place windows boot point at hd0,0 or sda1. Thus you would have something akin to this:

Note: The above instruction is in conflict with the GRUB installation position documented in GRUB#General notes about bootloader installation which says GRUB should be installed to MBR or the first partition to be recognized by most BIOS.
Note: It is also possible to install GRUB to MBR (/dev/sda). This works fine with Windows 7.
# 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 boot-up 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.
  • The file is read from the top down, so the system listed first will be the one to automatically boot, if no keys are pressed during the GRUB boot screen.
  • 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=sda1=hd0,0
First disk, second partition=sda2=hd0,1
Second disk, first partition=sdb1=hd1,0

Dual Booting from Multiple Hard Drives

To dual boot from two separate hard drives (e.g., one dedicated Linux drive and one dedicated Windows drive).

Windows + Arch

You have Windows installed on the first hard drive and you want to install Arch on the second one. Follow this procedure :

  1. Unplug the Windows hard drive (this is not needed if you are sure you know which drive have the Windows on it and which one is supposed to receive Arch. But this way you are sure you won't do any mistake)
  2. Install Arch on the second hard drive (that has become the first if you have unplug the Windows one)
  3. Be sure to install GRUB on the MBR on the Arch drive (I didn't test with syslinux but it should work too).
  4. At the end of the process you should be able to boot on Arch but not on Windows (the disk is unplug and even if not, GRUB doesn't know how to boot Windows... Yet !)
  5. Log in on Arch
  6. Edit /boot/grub/menu.lst (that needs root access),At the end add :
(2) Windows
title Seven
rootnoverify (hd0,0)
chainloader +1

I use '(2)' because '(0)' and '(1)' are already used by Arch.

If you want Windows to be loaded by default (the happy wife, happy life way !) Change the 'default' value by the one used for declaring Windows just before (here it is '2'). Ex :

# general configuration:
timeout   8
default   2

7/halt your computer and plug-in the Windows drive

8/Restart the computer. You should see the GRUB menu proposing Arch and Windows. Select the one you want et voila !

Arch + Windows

If Windows is not on the first hard drive, the Windows boot loader must be "tricked" into thinking Windows is on the first hard drive. Do this by adding the following lines to your menu.lst config file:

map (hd0) (hd1)
map (hd1) (hd0)

So the entry for Windows on second disk, first partition will look like this:

title Microsoft Windows XP Professional
root (hd1,0)
map (hd0) (hd1)
map (hd1) (hd0)
chainloader +1

Or if the above configuration doesn't work, you might try the one below from the Arch Wiki GRUB page:

title Windows
map (hd0) (hd1)
map (hd1) (hd0)
rootnoverify (hd1,0)
makeactive #if you use Windows7 this line should be commented out
chainloader +1

More information on GRUB configuration can be found in the GRUB manual.

Other Layouts

1. You could use:

Windows XP

and not use an extended partition (as /boot will be in the / partition as well).

2. LVM (Logical Volume Management) is also an option. You could simply create a single LVM partition and then create the other partitions inside the LVM physical volume. This allows a single partition to hold all your needed GNU/Linux data, and allows you to easily change partitions when necessary.

Notes on /home

You may not wish to store you documents on this mountpoint, especially if you wish to share data between both Windows and Arch Linux. Either use a shared NTFS partition (via NTFS-3G) or install Ext2Fsd in Windows, which will let you mount EXT4 partitions, even as Read-Only (a good idea in keeping the files virus-free).

Using Windows boot-loader

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 then loads arch.

Using Windows 7 Boot-Loader

Excerpted from http://www.iceflatline.com/2009/09/how-to-dual-boot-windows-7-and-linux-using-bcdedit/

This assumes you have already resized your Win partition, created Linux partitions, and installed linux. Some documents state that the partition being loaded by the Win boot-loader must be a primary partition but I have used this without problem on an extended partition.

  • When installing the grub bootloader, install it on your /boot partition rather than the MBR.
    Note: For instance, my /boot partition is /dev/sda5. So I installed grub at /dev/sda5 instead of /dev/sda
  • Under linux make a copy of the boot info by typing the following at the command shell:
mkdir /media/win
mount $my_windows_part /media/win
dd if=$my_boot_part of=/media/win/linux.bin bs=512 count=1
  • Boot to windows and run cmd with administrator privileges (navigate to Start->All Programs->Accessories, Right-click on Command Prompt and select “Run as administrator.”)
bcdedit /create /d “Linux” /application BOOTSECTOR
  • BCDEdit will return an alphanumeric identifier for this entry that I will refer to as {ID} in the remaining steps. You’ll need to replace {ID} by the actual returned identifier. An example of {ID} is {d7294d4e-9837-11de-99ac-f3f3a79e3e93}.
bcdedit /set {ID} device partition=c:
bcdedit /set {ID}  path \linux.bin
bcdedit /displayorder {ID} /addlast
bcdedit /timeout 30

Done! Reboot and enjoy. In my case I'm using the Win bootloader so that I can map my Dell Precision M4500's second power button to boot linux instead of windows.

Using Windows 2000/XP Bootloader

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 Linux bootloader; you will still need a /boot partition, and this one is arguably more difficult to set up.

See also

Booting Windows from a desktop shortcut