Dual-Boot Question

Hey all, I have a Windows XP Pro machine and a separate Gentoo machine. I would like to sell off the Gentoo machine except for the hard drive, then I want to put the gentoo hard drive in my XP rig so I can dual-boot with it. What's the best way to make this happen? I'm using lilo and I'm not sure how to go about it; it's been a while since I made my last dual-booter.

You have to install lilo (or any other bootloader) in the MBR of the harddisk you boot from so that it gets executed on startup.

If you install a second hard drive in the system though, it changes how the system will access the drive (what was /dev/hda will now be /dev/hdb, etc).

You will have to make some changes to your /etc/fstab in gentoo.

Okay, I've got both drives in the system. Lilo will properly load gentoo, but when I ask it to load windows it says "Missing Operating System". However, if I go through the BIOS and tell the windows drive to boot instead of the primary (gentoo) drive, then winxp boots just fine. Any ideas?

Several things possible, I can't really say which it is.

Lilo can't directly load windows, it must chainload it (same with grub). Make sure you have correctly configured lilo to load windows.

Also, adding the hard drive can bork your system because the drive numbers change. Your boot.ini on your windows partition might be pointing to disk 0, for example,which is where Windows was, but after adding the new hard drive, it's now disk 1, so when it looks on disk 0, it can't find it.

How are your hard drives connected now (which is master/slave on which controller) and how was each connected previously?

Make it that Windows is (in Linux lingo) /dev/hdaX and Linux is /dev/hdbX
Then install lilo in the MBR /dev/hda (the windows disk)
Your case looks like mixed disknumbers in the BIOS, ie windows will only boot when it's disk 0x80 and Linux will only boot if it's 0x80. What you need to do is make Windwos boot from 0x80, which it does automatically. And Linux boot from 0x81 which it doesn't it seems.

I used to have just the windows drive in this computer and the gentoo drive in another computer, but I'm moving and need to consolidate them so I placed the gentoo drive in as a slave on the same IDE channel as the windows drive (which was the master). When I did this, I used the BIOS boot menu to make sure gentoo would boot but it gives me a kernel panic error. I then changed the setup so that gentoo was the master and windows was slave and gentoo now boots; so does windows if I use the BIOS boot menu.

I also tried using NTLDR to dual-boot (using a small app called bootpart); it takes the first 512bytes of a drive and copies it to a file and tells boot.ini to use that file to load an alternate OS. I rebooted and the NTLDR menu came up, but whenever I selected gentoo it flashed and went back to the NTLDR screen - windows still worked though.

So if I have my gentoo drive as master and the windows drive as slave, you're saying that I need to edit boot.ini so that windows is thinking that it's disk 1 instead of disk 0?

Or would it actually be better to have windows as master and gentoo as slave as klingens said? Because then I would have to somehow sort out this kernel panic... I guess I would have to change something in lilo.conf from /dev/hda to /dev/hdb or something like that, right?

The master shouldn't really need any changes, as both were primary master before (if I read you correctly). If you make the gentoo the slave, you need to edit your /etc/fstab and grub.conf. If you make the windows the slave, you need to edit your boot.ini.

Or you can use the map feature in grub to just remap the drives do both think they are the master.

MRD said:

The master shouldn't really need any changes, as both were primary master before (if I read you correctly). If you make the gentoo the slave, you need to edit your /etc/fstab and grub.conf. If you make the windows the slave, you need to edit your boot.ini.

Or you can use the map feature in grub to just remap the drives do both think they are the master.

Click to expand...

Well, I'm using lilo right now but I know what to edit now.

In other news, I'm buying a 200gb hard drive tomorrow. I'll ghost the winxp drive to this new 200gb HD, then I'll use my current xp drive (which will be empty after I ghost it) to do a clean gentoo install. I didn't plan on doing this but I found this sweet deal over at CompUSSR (200gb for $79!).

Thanks for all your help!

Well, I got my new 200gb drive and ghosted winxp to it. I took my old 80gb drive and reinstalled gentoo on it and I just thought I'd let you all know that it was successful this time - thanks for your help!