[RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

jonnybarnes · 2015-12-20 11:34:59

I installed Windows 10 to a second hard drive I added to my desktop. To make sure nothing went wrong with grub/linux I unplugged the first hard drive during installation.

So I know have a system that is theoretically a dual-boot system. I just currently need to go into my BIOS and change the order it reads the hard drives in to change which OS is started!

Is there a way to have GRUB boot windows when installed this way?

Resolved: Everything still seems to be working

Last edited by jonnybarnes (2016-01-03 21:32:27)

ayekat · 2015-12-20 11:47:38

You could install os-prober and then regenerate your GRUB configuration:

# grub-mkconfig -o /boot/grub/grub.cfg

This should usually detect other operating systems and add entries for them. For Windows, it would typically add an entry for chain loading the Windows bootloader.

jonnybarnes · 2015-12-20 12:06:14

This doesn’t work

It creates a new entry in my grub menu, but when I select Windows 10 I then see the blue windows boot-up logo for about 2 seconds, then my machine restarts.

When I change the bios boot-up order to goto Windows directly it then complains about failing to start-up properly last time...

jonnybarnes · 2015-12-20 12:12:00

Of interest, Windows automatically formatted the second hard drive to have 500MB partition, and a second partition to use the rest of hard drive, GRUB is currently set to load the 500M partition.

Is this right?

ayekat · 2015-12-20 12:19:32

It's possible - from what I know Windows creates a separate "system partition" (pressumably containing the bootloader and kernel), so trying to boot from that one should usually work.

Are you using BIOS or UEFI to boot your system?

jonnybarnes · 2015-12-20 12:35:47

I'm using BIOS.

This is what is now in my grub.cfg:

### BEGIN /etc/grub.d/30_os-prober ###
menuentry 'Windows 10 (loader) (on /dev/sda1)' --class windows --class os $menuentry_id_option 'osprober-chain-DA202CDC202CC0FD' {
	insmod part_msdos 
	insmod ntfs
	set root='hd0,msdos1'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  DA202CDC202CC0FD
	else
	  search --no-floppy --fs-uuid --set=root DA202CDC202CC0FD
	fi
	drivemap -s (hd0) ${root}
	chainloader +1
}
### END /etc/grub.d/30_os-prober ###

And this is what fdisk prints out:

Command (m for help): p
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0xcdd53a6f

Device     Boot   Start        End    Sectors  Size Id Type
/dev/sda1  *       2048    1026047    1024000  500M  7 HPFS/NTFS/exFAT
/dev/sda2       1026048 1953521663 1952495616  931G  7 HPFS/NTFS/exFAT

I do find it kind of silly that the smallest hard drive I could buy today was a 1TB drive!

tom.ty89 · 2015-12-20 16:40:56

Bah os-prober still use the damn old chainloader +1 way? Is it even expected to work with later Windows?
You might need a custom entry which uses the ntldr command instead:
https://wiki.archlinux.org/index.php/GR … S-MBR_mode

jonnybarnes · 2015-12-20 17:00:02

Using the ntldr results in the same outcome, I see the blue windows boot-up logo for 2s then my machine reboots.

Head_on_a_Stick · 2015-12-20 18:25:13

tom.ty89 wrote:

Bah os-prober still use the damn old chainloader +1 way? Is it even expected to work with later Windows?

According to the official documentation, yes it is.

@OP: Try the drive swapping technique outlined in the link above, Windows will only boot if it is on the "first" disk.

EDIT: I see there is already a drivemap command in your grub.cfg -- try declaring the drives explicitly rather than as "${root}"

Last edited by Head_on_a_Stick (2015-12-20 18:28:00)

jonnybarnes · 2015-12-21 10:00:14

Okay, this still results in the windows logo for 2s then a machine restart:

menuentry "Microsoft Windows 10 BIOS-MBR" {
    insmod part_msdos
    insmod ntfs
    insmod search_fs_uuid
    insmod ntldr     
    search --no-floppy --fs-uuid --set=root DA202CDC202CC0FD
    drivemap -s (hd0) (hd2,msdos1)
    ntldr /bootmgr
}

tom.ty89 · 2015-12-21 11:46:38

What if you remove the line `drivemap -s (hd0) (hd2,msdos1)`?

jonnybarnes · 2015-12-21 12:48:39

This seems to have worked, thanks

tom.ty89 · 2015-12-21 13:41:41

Pfft that means os-prober is silly

But well grub-mkconfig is even sillier anyway, so write your grub.cfg: https://ptpb.pw/uhiV.cfg

Last edited by tom.ty89 (2015-12-21 14:57:08)

Archforum101 · 2015-12-21 14:50:43

Might look this over too. That nixer is dual booting Arch + win10 and worked for him. You'll just have to determine the right path cmd on your system to set grub2 as default. Works on this system too, several gnu/nix OS's and win8.1.

When comp boots up, I get right to the grub2 menu and win8.1 boots fine if selected. Your use case is slightly diff though, as you're dealing with 2 hdd's. Should still work though.

Last edited by Archforum101 (2015-12-21 14:51:45)

Arch Linux

#1 2015-12-20 11:34:59

[RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#2 2015-12-20 11:47:38

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#3 2015-12-20 12:06:14

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#4 2015-12-20 12:12:00

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#5 2015-12-20 12:19:32

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#6 2015-12-20 12:35:47

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#7 2015-12-20 16:40:56

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#8 2015-12-20 17:00:02

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#9 2015-12-20 18:25:13

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#10 2015-12-21 10:00:14

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#11 2015-12-21 11:46:38

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#12 2015-12-21 12:48:39

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#13 2015-12-21 13:41:41

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

#14 2015-12-21 14:50:43

Re: [RESOLVED]Setup GRUB to dual-boot Windows 10 on a second hard drive

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