Dual boot with two Hard Drives

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Kjammer · Post by **Kjammer** » Sun Nov 20, 2005 11:30 pm

I have two IDE Hard disk drives, wired as Master and Slave. They are currently partitioned as:

/dev/hda1 (boot) (Windows)

/dev/hdb1 (boot) (Linux)
/dev/hdb2 (Linux swap)
/dev/hdb3 (Linux)

What is the best way to go about installing Gentoo so I can have a choice on weather to boot Windows or Gentoo? The handbook seems to assume I'm using one PC with one HDD for Linux only.

superk · Post by **superk** » Sun Nov 20, 2005 11:41 pm

I have the same setup (sortof)

mine are

hda linux
hdb windows

in grub.conf I have

title=WINXP
map (hd0) (hd1)
map (hd1) (hd0)
chainloader (hd1,0)+1

this setup was the product of installing windows first, as it being the only drive attached, then linux drive was added.
I got it off of a thread in here but I do not remember which one. this is what I would recommend.

just be very carful about what you are doing to what drive

syg00 · Post by **syg00** » Sun Nov 20, 2005 11:45 pm

Basically just follow the handbook - for the grub root(...) directive, for your Windows use (hd0,0), for your Linux boot use (hd1,0).

For the kernel line, just use "root=/dev/hdb3". See how all that goes - hopefully the logic behind the changes should be clear.

As an aside, you do not need the map lines as posted by superk - they are only needed if Windows is not the first drive. The changes I mentiond should be all you need.

Kjammer · Post by **Kjammer** » Mon Nov 21, 2005 9:48 am

Thanks for your help on this matter. I'm still experincing some problems, most likely from something else (unrelated to grub). Right now /boot/grub/grub.conf looks like this:

Code: Select all

default 1
timeout 30
splashimage=(hd1,0)/grub/splash.xpm.gz

title=Gentoo Linux 2.6.13
root (hd1,0)
kernel /kernel-2.6.13-gentoo-r5 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=/dev/hdb3 vga=0x318 udev
initrd /initramfs-genkernel-amd64-2.6.13-gentoo-r5
title=Windows XP
root (hd0,0)
makeactive
chainloader +1

Is this the correct syntax?
BTW I used genkernel to configure the kernel.

EDIT: the space in splashimage was a typo on the forum not in grub.config

syg00 · Post by **syg00** » Mon Nov 21, 2005 10:38 am

Looks pretty good, except loose the space in the splash line - in fact I recommend you comment it out (# in column 1) until you get everything else sorted.
I'd also be checking those filenames (kernel and initrd).

SonicPadawan · Post by **SonicPadawan** » Mon Nov 21, 2005 5:42 pm

Kjammer wrote:I have two IDE Hard disk drives, wired as Master and Slave. They are currently partitioned as:

/dev/hda1 (boot) (Windows)

/dev/hdb1 (boot) (Linux)
/dev/hdb2 (Linux swap)
/dev/hdb3 (Linux)

What is the best way to go about installing Gentoo so I can have a choice on weather to boot Windows or Gentoo? The handbook seems to assume I'm using one PC with one HDD for Linux only.

I have a pre-existing windows installation and am adding a new drive for a Gentoo install. What I've decided to do is put the Windows drive as the slave and make Gentoo the master drive. Since Windows can't recognize the file system type of Linux I'd imagine Windows would ignore it and declare itself the sole drive and therefore drive c: (thus not changing file paths).

This is all in theory for me since I'm having quite a bit of trouble getting 2005.1 to mount the CD drive during install. Regardless, I'm in a similar situation and thought I might share my perspective.

sundialsvc4 · Post by **sundialsvc4** » Mon Nov 21, 2005 9:11 pm

Some computers can, in their BIOS, allow you to directly select the boot-drive. Some computers even have a "profile" option in the BIOS from which an entire group of settings can be selected at-will.

A friend of mine used a toggle-switch on the two disk-drive power cables. (Seriously!)

If this isn't working for you, try setting the BIOS to startup on the Linux partition .. the slave .. and configure Grub to allow you to select Windows or Linux. There's plenty of documentation with Grub on exactly how to do this. The advantage of this is that you can do it without making any change whatsoever to the existing Windows config.

Windows will see Linux's partitions but won't know what to do with them. ("Not From Redmond" Error.) Linux will see the Windows partition ("Yuck!!") and can either use them or ignore them as you please.

SonicPadawan · Post by **SonicPadawan** » Tue Nov 22, 2005 3:37 am

sundialsvc4 wrote:If this isn't working for you, try setting the BIOS to startup on the Linux partition .. the slave .. and configure Grub to allow you to select Windows or Linux. There's plenty of documentation with Grub on exactly how to do this. The advantage of this is that you can do it without making any change whatsoever to the existing Windows config.

I'll try this as you described. Excellent suggestion!

SonicPadawan · Post by **SonicPadawan** » Wed Nov 30, 2005 12:11 am

I just wanted to confirm that this worked, and worked well (not that anyone had a doubt).

Windows on Master, Linux on Slave, BIOS set to boot to Slave.

Many thanks for this timely post!

sundialsvc4 · Post by **sundialsvc4** » Wed Nov 30, 2005 10:18 pm

Great! Glad I/we could help!

The admonition not to change the master/slave status of the Windows drive is that ... the drive will move, change device-numbers, if you do that, and Windows will certainly notice that. By leaving the drive exactly where it is, Windows is undisturbed. It will observe that "a new drive has been added, containing no partition-types that I am prepared to deal with," but it will see no significant changes to itself.

Blitzace · Post by **Blitzace** » Thu Dec 01, 2005 6:56 am

Yeh I'd be careful moving the hard drive, windows might want you to activate it again because you changed some hardware! (I'm serious I added 512 of ram once and it asked me to put in my Serial Code again!)

Dual boot with two Hard Drives

Dual boot with two Hard Drives

Re: Dual boot with two Hard Drives

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