grub repair fails on dual boot

[ubuntu-users-list at thomas.freit.ag]

Hi Liam,

On 07.04.24 15:24, Liam Proven wrote:
>> after some Windows 10 updates, dual boot (Windows 10 and Ubuntu 23.10) does not work any more on my Lenovo Ideapad 5. After turning on, grub does not get invoked and it boots directly into Win
>> 10. This happens sometimes, booting a USB live system and reinstalling grub usually works fine. However, this time reinstalling does not work. After attempted repair, still no grub is loaded
>> on bootup and system ends in BIOS or boots Win 10 (depending on boot order).

> Have you disabled secure boot?
> Have you disabled Windows Bitlocker?

It was an issue with secure boot, Lenovo specific and with no errror messages indicating this. Rerolled the Canonical certs and now it boots again. Most helpful (however no step by step guide) 
was: https://answers.launchpad.net/ubuntu/+question/700326

>> 2) prepare the live system for grub (re)installation, make sure chroot has all necessary stuff
>> # cryptdisks_start nvme0n1p6_crypt
>> Starting crypto disk...
>> nvme0n1p6_crypt (starting)...Enter passphrase for /dev/nvme0n1p6:
>> nvme0n1p6_crypt (started)...done.

> Hey hey hey whoah there.
> You didn't mention disk encryption.
I use an unencrypted boot, with LUKS encrypted / and /home, I pretty sure this was not a problem in this case. No issues since years.

> 1. Don't dual boot with disk encryption.
> 2. Better still, don't use disk encryption.

This is a rather dangerous hint. I would strongly suggest to use encryption whenever possible, especially for devices which are transportable. In case of loss or theft this is vital to protect 
your data. Hardware is fast enough for years and LUKS is a well established stack.

Regards,
Thomas