Re: Can't boot Win 7 on second HDD from Kubuntu Trusty GRUB

[Andrei Borzenkov]

On Tue, Oct 27, 2015 at 5:42 AM, Shriramana Sharma <address@hidden> wrote:
> Hello.
>
> I have a system with three hard drives: 320 GB SATA, 80 GB SATA and 80
> GB IDE, and in that order I have configured the BIOS boot order.
>
> I have freshly installed Kubuntu Trusty on the 320 GB SATA disk and
> Windows 7 on the 80 GB SATA disk, both on the first partitions of the
> respective drives. Kubuntu shows the BIOS drives as sdb, sdc and sda
> respectively, which is OK by me so long as Kubuntu works fine.
>
> Now GRUB has no problem booting to Kubuntu. If I set the Windows disk
> as the first disk in BIOS, then I have no problem booting Windows
> directly either. However, when booting from GRUB I am not able to use
> the Windows 7 GRUB entry created by GRUB's OS-prober, since it just
> reboots the system.
>

Could you show full menu entry?

> As per the GRUB manual's advice regarding this issue
> (https://www.gnu.org/software/grub/manual/html_node/DOS_002fWindows.html#DOS_002fWindows)
> I have added the following simple entry in /etc/grub.d/40_custom (and
> disabled /etc/grub.d/30_os-prober to avoid two Windows 7 entries):
>
> menuentry 'Windows 7' {
>     insmod part_msdos
>     insmod ntfs

Neither is needed if you are going to chainload MBR anyway.

>     drivemap -s (hd0) (hd1)
>     chainloader (hd0)+1

That still tries to load MBR from original hd0, not hd1.

> }
>
> but it says "invalid signature". If I go to the GRUB command line and
> do the drivemap -s, then even afterwards, ls (hd0,msdos1) shows the
> contents of the Kubuntu partition and not the Windows partition.

That's correct. drivemap arranges for TSR code to be loaded
immediately before jumping to loaded code. As long as you are still in
GRUB, you see original drive names as determined by GRUB.

> Perhaps this is why chainloader doesn't work? Then I tried chainloader
> (hd1)+1 from the commandline, but this still reboots.
>
> Please help.
>
> --
> Shriramana Sharma ஶ்ரீரமணஶர்மா श्रीरमणशर्मा
>
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