No Windows access in my dual-boot system, grub misconfigured

javipas · 2012-02-24 16:14:00

I usually work with Windows and several Linux distributions, and from time to time I have had problems with GRUB configs. Those problems dissapeared mostly with GRUB2, but when I've tried to install Arch Linux (my first time to test Arch native, not in a VM) I've found myself without easy access to my Windows system, which I prefer for some tasks (and games).

I've tried to follow the Arch wiki guidelines for dual boot configurations (https://wiki.archlinux.org/index.php/Wi … _Dual_Boot) and according to my current system configuration, I should just add these lines to my grub configuration file, the traditional /boot/grub/menu.lst:

title Windows7
map (hd0) (hd1)
map (hd1) (hd0)
rootnoverify (hd1,0)
# makeactive #I use W7
chainloader +1

But these don't work, and I thought they shoud. My config is as follows:

/dev/sda -> old disk I still use for several data partitions
/dev/sdb -> SSD with:
/dev/sdb1 -> Windows
/dev/sdb2 -> /boot
/dev/sdb4 -> /
/dev/sdb5 -> swap
/dev/sdc -> more data partitions on another HDD

Maybe my fault is installing grub on /dev/sda, something that maybe I should change, but I guess there is some trick that could make it work modifying that lines. Maybe the map ones, I'm not sure.

Any ideas?

Oxyd · 2012-02-24 16:29:26

Since you remapped (hd0) ↔ (hd1), shouldn't that be rootnoverify (hd0,0), instead of (hd1,0)?

If that fails, I'd try removing the remapping and then using rootnoverify (hd1,0).

Also you can try entering the GRUB shell (when the thing boots, not from your running Arch), and try to boot Windows “manually” – type in the rootnoverify and chainloader +1 commands – at the shell you'll have the advantage of tab completion which can hint you at what the correct partition is.

DSpider · 2012-02-24 20:41:07

I have Windows set up on sdb2 (second partition of the second disk), and it's Windows XP, mind you - which absolutely hates not being the 1st drive, 1st partition (yeah, suck it, Microsoft!). The only thing is that I have GRUB 2 installed, not GRUB Legacy.

Here's my /etc/grub.d/11_Windows file:
(you may wanna substitute the "XP" part with "7", it works just as well)

#! /bin/sh -e
echo "Adding Windows XP..." >&2
cat << EOF
menuentry "Windows XP" {
set root=(hd0,2)     «— (hd0,1) in your case. Remember, GRUB 2 counts partitions starting from 1.
chainloader +1
}
EOF

All that's left is generating a grub.cfg and that's it.

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

Last edited by DSpider (2012-03-04 12:47:54)

shulamy · 2012-02-24 22:10:32

i think only one map is needed.

look in man grub.

and i whuld install grub on the second disk.

ezik

akspecs · 2012-02-26 09:31:29

I reccomend installing os-prober if you haven't.
>pacman -S os-prober

run the program once for fun to see if and how it works. once you're done with that run this:

>GRUB_PREFIX="/boot/grub" grub-mkconfig -o /boot/grub/grub.cfg

that should generate the a config file and automatically put in the correct information regarding the windows partition(s) - and other OS's for that matter.

If you still have problems, consult the grub2 wiki which is actually very helpful if you're trying to make your grub2 do some fun tricks. If you're stuck with that, or if windows appears to still be unbootable I would ask you what partition scheme you're hard drives are using.

https://wiki.archlinux.org/index.php/GR … onfig_file

javipas · 2012-03-04 11:53:36

Thanks for the suggestions: I was in a hurry so I installed Ubuntu 12.04 (a daily cd) and the install process solved all the issues with a GRUB 2 menu that was OK for booting Arch, Windows and Linux. I feel more comfy with Ubuntu right now, and I'm starting to use Arch, but I supposed grub wouldn't give me that problems.

Anyway, I had spare space on my hdd so I finally did this and this way I can also test the latest Ubuntu from time to time.

Thanks for your help!!

Arch Linux

#1 2012-02-24 16:14:00

No Windows access in my dual-boot system, grub misconfigured

#2 2012-02-24 16:29:26

Re: No Windows access in my dual-boot system, grub misconfigured

#3 2012-02-24 20:41:07

Re: No Windows access in my dual-boot system, grub misconfigured

#4 2012-02-24 22:10:32

Re: No Windows access in my dual-boot system, grub misconfigured

#5 2012-02-26 09:31:29

Re: No Windows access in my dual-boot system, grub misconfigured

#6 2012-03-04 11:53:36

Re: No Windows access in my dual-boot system, grub misconfigured

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