Dual boot - Gentoo & Windows

Hello folks.

I have Gentoo installed on my hard drive.

Partition 1 - Gentoo boot - 100 MB
Partition 2 - Gentoo swap - 4096 MB
Partition 3 - Gentoo root - 70,000 MB

The rest of the hard drive is unpartitioned space ( about 225 GB unpartitioned )

I would like to Install windows on that unpartitioned space and dual be able to dual boot.

Or if that's not possible, then I can even consider getting a second hard drive and using that for windows dual boot.

I hear this is not possible due to windows taking over the MBR.

Please let me know.

Thanks!

It's possible, it's just that Windows will overwrite the bootloader so you'll have to reintall it:

• Boot to your Linux install CD and type "linux rescue" at the boot prompt.
  
• Answer a bunch of questions about language and keyboard settings
  
• chroot /mnt/sysimage
  
• fdisk /dev/hda (assuming /dev/hda is your primary hard drive, may be /dev/sda)
  
• enter "p" and make note of the NTFS partition (that's your Windows partition)
  
• enter "q" to quit
  
• open your grub.conf in an editor:
  vi /boot/grub.conf
  
• Add something like the following:
  
  Code: [ Select ]
  title=Windows XP
  rootnoverify (hd0,5)
  makeactive
  chainloader +1
  
  1. title=Windows XP
  2. rootnoverify (hd0,5)
  3. makeactive
  4. chainloader +1
  
  That's taken directly from the Gentoo docs. The hard drive hd0,5 is the first hard drive (grub starts from 0) and the 6th partition, so here Windows exists on /dev/hda6.
  
• Reinstall grub to the mbr
  
  Code: [ Select ]
  grub-install /dev/hda
  

When you reboot, you'll have an option for Linux and Windows (theoretically).

*edit*
Just a note that you may want to make a FAT32 partition to store data in that you can natively view and write to under Linux (without having to build in NTFS support). You can then use this as a shared area between both operating systems.

Thanks so much for your reply. I really appreciate it.

So to clairfy, do I complete the above steps AFTER I install windows on the machine that currently has gentoo installed?

Also. Since gentoo is already installed, how will windows know to install itself on the "unpartitioned" area?

Since I chrooted into a directory, do I have to come out of that chrooted environment before rebooting?

Edit:

the idea of the FAT32 partition is a good one. Samba is also another consideration I had.

Yes, you perform the above steps AFTER you've installed Windows

The Windows installer should ask you where you want to install it, one of the options here is to create new partitions and then choose which partition to install Windows on. If you want the Fat filesystem, DO NOT choose to "Install Windows on the Unpartitioned Space" as this will format all of the free space on the drive to NTFS. I don't know if the Windows installer will allow you to create FAT partitions anymore either, so you may want to do that under Linux. If you installed Gentoo, the steps are the same to create the partition, then mkfs.vfat to format it.

Since you're in a chrooted environment, the standard way is indeed to exit that environment before rebooting. However, since your "real" environment is virtual (the OS is running in memory), you're not going to hurt anything by issuing "reboot" or "/sbin/shutdown -r now" from within the chrooted environment.

You won't be able to use Samba to communicate from one OS to the other on the same system unless you set up some form of virtualization to have both running at the same time. Hence the need for a vfat filesystem. You could just as easily compile your kernel with NTFS and NTFS-Write support (see under Filesystems somewhere) which would negate this need. Personally, I don't trust NTFS nearly as much as I do vfat under Linux. If only Windows could read Reiserfs.

Yeah. I've used reiserfs for my root partition. First time I've used it. I'm really interested to see what the differences are going to be from the ext3 i've used before and NTFS on windows.

thanks again for the clear explanation. I appreciate it! This will be much help.