Dual Boot Dual Disc - Grub problem ? when reordering boot sequence & back (24.04.3 LTS)

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I’ve just done a clean install of Windows 10 onto one SSD and then installed Ubuntu Mate 24.04.3LTS onto a 2nd SSD, with Grub also on the 2nd SSD. ( I used the 3rd custom install option on the installation media)

I had seen comments saying this approach is safer/more retrievable, than a dual boot single SSD setup, should grub get corrupted. The Install worked, with Grub as the default boot and both OS options booted up from the grub menu. It also worked with secure boot back on. However, I then tried changing the boot order in the UEFI setup/boot menu. With Windows at top of list and it booted to windows without the grub menu ( as expected)…..

…..but when I returned the order to Ubuntu at top of the boot menu…it still booted to Windows. I presume Grub is corrupted or it is not now in the right place to be found?? ( I am a novice…so I’m guessing)

Should it be possible to change the boot order without damaging grub?

(I have reinstalled Ubuntu Mate and the dual boot set up is working again….. I am happy with how it works…..but at some point I presume I will want to change the boot order …e.g if I need to repair/reinstall windows)

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Hello, @hoogerbooger and welcome to the Ubuntu MATE Community!

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I hate grub. I break out in hives every time I see a grub menu.

I had similar problems when I basically did the same thing you did and this tool works wonders and should help you.

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Good advice from GeekBone, Grub Customizer is not available for 24.04 but you can install it from a ppa: https://www.cherryservers.com/blog/install-grub-customizer-ubuntu

I’ve no idea why it was removed from the repos, it has been pretty much essential if you want multi-boot setups for quite some time.

Install it and use it to configure grub to automatically boot the last booted OS, then the order in the boot menu becomes merely cosmetic, and Grub Customizer gives you fair amount of control how the grub menu looks and now long it waits.

I’ve needed both on multi-boot setups with Windows and 24.04

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The issue with Grub, Windows, Linux and trying to have a stable/robust multi-boot configuration ... is that Windows doesn't play nice with anything that relates to Linux!

For that reason, I will never have a dual Linux and Windows boot, except in the following manner:

  • dedicated disk 1: Pure Windows installation, with Windows only boot-loader

  • dedicated disk 2: Linux with os-probe from update-grug building menu offering boot from either Linux or Windows

To boot directly to Windows, I would switch BIOS boot priority order to look at disk 1 before disk 2. Otherwise, I would have BIOS boot priority order always look at disk2, and choose disk 1 from the Grub menu offerings, if the "urge" strikes me!

:slight_smile:

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Many Thanks all. Will investigate Boot-Repair & Grub Customizer further.

RE ericmarceau’s advice on dual-boot approach: that is what I think I’ve done.

On Disc 0 is Windows….with the 4 partitions windows sets up ( although I’ve now created from the C:\ drive an extra partition/drive for any documents I might want to share/access between OS’s)

On the smaller Disc 1 is Ubuntu and I see 2 partitions, the small 1st partition (when viewed on aomei Partition Assistant) is labelled “GPT, EFI System Partition” …and I presume is Grub

I am hoping that means all of GRUB is on Disc 1 ?

(But That leaves me ( as a novice) mystified as to why just changing the boot order there and back caused the Grub problem. BUT I will get on with using the system and get my head around the boot repair process)

Thanks

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Just to complete…this is the boot order in UEFI….as set by the Ubuntu Mate installer.

For my info…is No. 1 on the list “Ubuntu” … referring specifically to the Grub partition? ( which seems to be the 1st partition on my Disc 1).

(I am a tad unsure why it has the 2 SSD’s separately on the list and the useful purpose that provides? I’m guessing it relates to having 2 separate boot partitions to find…which may both be on the same disc )

ericmarceau suggests I should move my ubuntu drive HDD1 (above) up to No3( or 2) to be above the Windows boot manager. I Am a bit nervous about trying this….but I guess better to do it now than later. But I do not understand how this would resolve the problem I had before…unless grub itself wasn’t corrupted…..but just somehow couldn’t be found ? why would changing the boot order in UEFI affect the physical boot locations ?

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The “best” multiboot setup I ever had has with a computer that had a function key dedicated to opening the BIOS boot menu, then the one drive per OS setup was as trouble free as I imagine would be possible, as each OS got its own boot system independent of any others. This seems to be a very rare thing, although I don’t have access to the variety of hardware that I used to before I retired.

It could change the device mapping, i.e. which drive is /dev/sda or /dev/nvme0 etc. But I though grub boot by UUID was supposed to fix this problem.

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I am sorry. I incorrectly assumed you had more awareness of the intent/function/approach to BIOS/UEFI Boot Priority ordering and its impact on what you can/cannot do. I will try to correct that now.

The items at the top should be the "plug & play" devices which offer the option to use an "outside" boot image, such as a USB stick, USB hard drive, USB optical drive.

Looking at your list that would mean that the devices at the top of your boot order priority should be:

  • USB HDD (for external USB hard-drive or USB stick drive)
  • USB CD (for external CD/DVD/BluRayDisk)

IF you ever plan to use a Floppy Disk Drive, then the next item from your list should be

  • USB FDD

However, if you can, and want, to make that go "poof" because you can't imagine ever reverting to 30 year-old technology, then you should be safe delete that option, if possible.

Next in the priority order would be internal devices that are "optional", meaning "Use if disk in device", such as:

  • ATAPI CD (for internal CD/DVD/BluRayDisk)

Next in priority order would be (usually only in Corporate environment) the Network-based boot capability, which is offered by

  • PCI LAN: EFI Network (IPv4)
  • PCI LAN: EFI Network (IPv6)

But since I think you are talking about a strictly Personal, Home, Desktop computer, like for the case for "USB FDD", the should be highly unlikely and, again, I recommend you put those two at the very bottom of your priority list. I don't know enough about your setup to even suggest whether it is appropriate, let alone dangerous, to consider "deleting" those two. Seek other more knowledgeable advice on that before proceeding!

Next would be the known bootable drives,

  • Ubuntu
  • Windows Boot Manager

and lastly would be the other hard drives (or partitions) with a recognized boot image, if you have more than one boot image on the same disk:

  • ATA HDD: Kingston ...
  • ATA HDD1: Kingston ...

To avoid messing with your Windows, and to avoid having Windows mess with your Ubuntu, ALWAYS have Ubuntu earlier on the priority list than your Windows device.

Hope that helps!

:slight_smile:

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Many thanks for the expanded advice ( and all).

I have managed to move USB HDD up to the top of the boot order and then back below Ubuntu without mishap to the dual boot ( leaving Windows boot Manager at 3).I will only boot Windows from Grub ( well at least until Grub fails!)

This will do for my “general punter” laptop use and I am now better equipped for any future fixing need….

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"update-grub" will always save the "GRUB" config/boot on the "primary" drive, which is always the first drive, per boot priority sequence, which has a bootable OS, Linux or Windows.

Since Windows doesn't "play nice" with GRUB, it is best to make any Windows drive "invisible" to GRUB while trying to update the boot configuration for GRUB. Hence the directive to unplug all such drives before performing the BOOT REPAIR activity.

Any previous GRUB setup on the Windows disk will be left untouched but, if it was "modified" from Windows to work "a la Windows", it is best to leave the Windows-specific boot config (with GRUB or not) asis for use by Windows when telling the system to boot from the Windows disk (even if that is by menu selection on the Linux boot menu).

If there was ... NO ... GRUB on the Windows disk before, there won't be any after the BOOT REPAIR done the way I outlined.

If there ... WAS ... a GRUB on the Windows disk before, it will still be there, but that will remain untouched by any GRUB-related updates performed from Linux.

Hope that clarifies. :slight_smile:

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