Re: A further question on my "how to move to an NVME disk" question

[sashab]

Hi Chris,

for trial'n'error you could
    mount /dev/nvme0n1p2 /mnt
and try if
    update-grub
tells you about any "other" OS'es found.
(There sould be an os-autodetect script supplied with the grub package.)


If this doesn't work, I'd suggest to
enter grub shell on boot and check if you're
able to
    ls
your nvme disk there.

If you can, "update-grub" did something wrong
or the script mentioned above is missing.
In that case I would add a custom boot entry in 19.04 like
    echo 'menuentry "19.10" {configfile (hdX,gptY)/boot/grub/grub.cfg}'\
    >> /etc/grub/40_custom
with (hdX,gptY) replaced with the label you saw in grub shell.

If not, reboot to 19.04 and
    mount /dev/nvme0n1p2 /mnt
    rsync -ahP /mnt/boot/*vm*linu* /boot/
    rsync -ahP /mnt/boot/*ini* /boot/
    grep /boot /etc/fstab >> /mnt/etc/fstab
    update-grub
If it still doesn't work, you could
    cp /mnt/boot/grub/grub.cfg /boot/grub/grub_new.cfg
and try to load the config from the grub shell on reboot.

Hth

Regards,
    sashab

On 11/21/19 7:20 PM, Chris Green wrote:
> Thanks for all the replies and help for my original "How to install
> grub onto an added drive?" question.
> 
> I actually have my nice new NVME SSD and PCIe adapter now and, quite a
> pleasant surprise, they "just work". My existing xubuntu 19.04
> installation recognises the drive and I've used fdisk to partition it
> and mkfs to build a file system.
> 
> As an experiment I unplugged all the other drives and tried to install
> xubuntu 19.10 on the new drive.  It completed the installation without
> any errors but, not surprisingly, the system complains about there
> being no boot device when I try and boot it.  So, confirmed, I can't
> boot from the new NVME drive.
> 
> So, I have thought a bit and I'm wondering if my best strategy might
> be to dual boot xubuntu 19.04 and 19.10 for a while, this way I'll get
> a 'clean new' 19.10 installation and the old 19.04 installation files
> will be available to look at to copy configuration across.
> 
> Finally to my question!  How do I simply add xubuntu 19.10 as a boot
> option to my existing set up?  As things stand the xubuntu 19.04 OS
> and /boot are all on /dev/sdb1 which is a SATA SSD.  So it would make
> sense to simply add the ability to boot the xubuntu 19.10 installed on
> /dev/nvme0n1p2 to the existing /boot.  How do I do this?
>