Re: problems dual booting Ubuntu 16.04 and Windows 10

[Pascal Hambourg]

Le 15/05/2018 à 06:57, David Collier a écrit :
> > address@hidden:/# update-grub
> > > Generating grub configuration file ...
> > > Warning: Setting GRUB_TIMEOUT to a non-zero value when
> > GRUB_HIDDEN_TIMEOUT
> > > is set is no longer supported.
> > > Found linux image: /boot/vmlinuz-4.13.0-41-generic
> > > Found initrd image: /boot/initrd.img-4.13.0-41-generic
> > > Found linux image: /boot/vmlinuz-4.13.0-39-generic
> > > Found initrd image: /boot/initrd.img-4.13.0-39-generic
> > > Found linux image: /boot/vmlinuz-4.13.0-38-generic
> > > Found initrd image: /boot/initrd.img-4.13.0-38-generic
> > > done
> >
> > I do not see the other systems detected by os-prober.
> > Check the options in /etc/default/grub.
>
>   These are the only uncommented lines in /etc/default/grub
>
> vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
> GRUB_DEFAULT=0
> GRUB_HIDDEN_TIMEOUT=0
> GRUB_HIDDEN_TIMEOUT_QUIET=true
> GRUB_TIMEOUT=10
> GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
> GRUB_CMDLINE_LINUX_DEFAULT="quiet splash ipv6.disable=1"
> GRUB_CMDLINE_LINUX=""
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I expected to see an option such as GRUB_DISABLE_OS_PROBER which would 
explain that update-grub does not report the lines detected by 
os-prober. But there is none. Does /etc/grub.d/30_os-prober exist and is 
executable ?

Commenting out the two GRUB_HIDDEN_TIMEOUT options should suppress the 
warning when running update-grub and restore the menu.

> What I meant to say was that running ls in grub command line mode (which I
> can't do presently, as the system does not stop at grub menu at boot any
> more :), it was showing two boot partitions, one on hd0 and one on hd2
> IIRC, but I still could not manage to force it to boot from the partition
> which seemed to be the windows boot partition.
>
> before all these exercises grub in the command line mode was showing only
> one boot partition.

"ls" does not show only boot partitions (whatever "boot" means), it 
shows all detected partitions. Detecting partitions requires that the 
disk holding them is detected and the module supporting the partition 
table format is loaded.

insmod part_msdos
insmod part_gpt

If you want to boot Windows manually from GRUB, you can use the 
following commands, assuming hd0 is the boot disk containing the EFI 
partition (sdc) :

set root=(hd0,gpt2)
insmod fat
chainloader /efi/Microsoft/Boot/bootmgfw.efi
boot