[MULTI BOOT] Lost dual. How do I quickly restore Linux dual boot

[CharlieDaves]

After updating BIOS, I've lost the kali linux dual booting. Files and drives are still there.
I've read through all including my previously asked question about dual booting, and I am getting confused

is there a cmd that restores 'grub' to the boot drive?

current fstab shows (APPEARS) linux still there

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# systemd generates mount units based on this file, see systemd.mount(5).
# Please run 'systemctl daemon-reload' after making changes here.
#
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/nvme0n1p5 during installation
UUID=afc7d3b5-cc4b-4ebd-b534-1f5c7e6ff8bc / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/nvme0n1p1 during installation
UUID=281D-C70A /boot/efi vfat umask=0077 0 1
# swap was on /dev/nvme0n1p6 during installation
UUID=5e36ad90-d64e-4e7f-b416-d71ad9e11ccb none swap sw 0 0

[claydoh]

look at your bios settings, the update probably reset some things, and maybe changed the boot order. Also, you can get to a bios boot menu from the f12 key when powering on, though it could be a different fkey.

Each linux OS, and Windows, will have its own separate boot loader, and often the last OS installed sets itself at the top of the list in the Bios settings. Windows updates can do this as well. You should be able to go in and change the order in the bios.
The bootloaders are not broken, just likely re-arranged. It IS confusing because each Linux grub boot loader can boot all the other OS, if they are manually updated when adding a new distro, or the when there are updates to the kernel in previously installed distros.

[Fred47]

Sounds like what happened to my HP laptop. The bootloader DELETED my Linux command and I had to reinstall. Like you the files are still there, so I was able to backup. I now have 2 laptops one for Windows and one for Linux.

[jlittle]

is there a cmd that restores 'grub' to the boot drive?

The answer to your question is grub-install. It's normally run by the installer, or by update-grub. But, normally you'd run it from Kubuntu, and running your Kubuntu is difficult.

Super Grub2 disk is designed to do just that. It's only a 16 MB download.

In theory you could boot a live *buntu USB (in UEFI mode), mount the Kubuntu partition and the ESP, then run a grub-install command specifying --boot-directory and --efi-directory set to the right places. I can't test that so I'm reluctant to give detailed instructions.

[CharlieDaves]

mount the Kubuntu partition and the ESP, then run a grub-install command specifying --boot-directory and --efi-directory set to the right places. I can't test that so I'm reluctant to give detailed instructions.

Ehat is ESP (Besides Extra Sensory Perception)

Is there anyway of installing grub from Windows? I've read a couple of articles claiming you can, but they seam a tad dodgy for me.

[jlittle]

The ESP is part of the UEFI (Unified Extensible Firmware Interface), which specifies the EFI (as before) System Partition. It's always had the label "EFI" in my computers. It's usually the first partition, its type is fat32, and is small, typically a few hundred MB. It's designed to be shared by all the operating systems on the computer, including Windows and Kubuntu.

I'm sure someone at some stage has made a grub installer for Windows, but where would you get it? I'd worry about malware, unless it came from the Windows store, and that seems unlikely.

[claydoh]

So, it seems my Lenovo Flex15iiL just had a new bios update released this past week.
And guess what? It reset some settings, such as the boot order selection....go figure
It also reset my Fn-keys to use the secondary functions (volume, etc) as the primary action. This I am used to from past updates on multiple Lenovo laptops.

Note that the Windows boot option is obvious, while the Linux one is not, in my case at least. Easily fixed by moving the other boot loader entry to the top.
F2 during starup should get you to the settings, and f12 should get you a one-time boot selection to choose which OS boot loader to use.

Now, see if you have similar settings - I will wager that we have very similar Bios menus considering the brand and similar age/hardware generation

[CharlieDaves]

the BIOS update run from Microsuxs screwed mine.

[claydoh]

Odd af, to be sure

If you have an NVME drive, you might check that it hasn't set it to use Intel RST /Raid or something - it should be set to AHCI, though if this were the case, you would not see any of your Linux files, as you mentioned.
I don't know Kali, other than it ostensibly is not meant to be installed to a drive, so I don't know if the way they set things up might affect this.

You also haven't mentioned Kubuntu, was this also installed?

In any case, you can use a live disk to reinstall/repair grub, though there are is also a specialized boot repair disk to try
https://sourceforge.net/p/boot-repair/home/Home/
or you can actually install and run it from a *buntu live session
https://help.ubuntu.com/community/Bo...ng_Boot-Repair

[Fred47]

I felt no one believed me when I said a MS update deleted my boot entry for Linux, but that is clearly what has happened to you as well. It happened to me twice! So I no longer dual boot. I keep MS on my old laptop and drag it out once a year to do my taxes.

[jlittle]

I felt no one believed me when I said a MS update deleted my boot entry for Linux..... I keep MS on my old laptop ...

Windows used to do that a lot...(at least, I would hear about it a lot). It's been better behaved in recent years. It was a problem even for Windows only techies who needed to run several versions. Maybe your Windows is old enough to suffer from that.

[Fred47]

Windows used to do that a lot...(at least, I would hear about it a lot). It's been better behaved in recent years. It was a problem even for Windows only techies who needed to run several versions. Maybe your Windows is old enough to suffer from that.

Windows 10?