Re: Boot windows on external disk : "not a valid root device"

[Hervé Guillemet]

Le 02/01/2013 01:14, Colin Watson a écrit :
> On Wed, Jan 02, 2013 at 12:31:14AM +0100, Hervé Guillemet wrote:
>> I have a new Asus N56VZ laptop and replaced the Windows hard drive by a
>> SSD with Linux installed. EFI Grub2 successfully launchs Linux.
>> Now I'd like to boot Windows from the original hard drive mounted by USB.
>>
>> No matter what I try, either using grub.cfg or command line, Grub's
>> chainloader fails :
>>
>>> set root=(usb0,gpt1)
>>> chainloader ($root)/EFI/Microsoft/Boot/bootmgfw.efi
>> Error: not a valid root device.
>>
>> The content of the drive may be seen using "ls".
>>
>> What's the exact meaning of "not a valid root device" ?
> 
> It indicates that either no UEFI device handle corresponding to that
> device was found, or that no UEFI protocol interface is available for
> that device handle.  In other words, "can't work out how to talk to that
> device using UEFI".
> 
> I think your device naming is dubious: as far as I can see, GRUB's
> efidisk module does not fully support calling a disk "usb0".  The "ls"
> command should show you the list of available disks and partitions, or
> you can type "set root=(" and then use tab-completion.  If the disk is
> truly only accessible as "usb0", then perhaps efidisk needs some work to
> support that.

I confirm than the "ls" and tab completion after "(" list me hd0, my
internal SSD, and usb0 (with all gpt partitions).


-- 
Hervé