Grub Config Changes with LMDE6 Install / Changes Boot Order of Debian and Slackware:

[UltimateCat]

Upon installing LMDE6 I've had unusual behavior with Grub and other unexplained issues on a friend's custom built desktop as well.

After installing LMDE6 on my bf's desktop and removing the installation media the first boot lead to only having the grub rescue> prompt.
I used a Debian 12 Live USB to re-install Grub and rebooted. Still had the 'grub rescue> prompt' and the funny thing was all of my friends partitions were still in place and the boot info. script confirmed that
Grub was installed to all 3 of his HDD's.

Having the thought to look into the BIOS I discovered that the boot order that I originally set was switched around completely.
I helped my friend to get his drives back into the order in which they originally were with /dev/sda (SSD) first, /dev/sdb (Hitichi) second, and /dev/sdc (WD) last in the boot order.
Rebooting was a success and he had Grub.

Since installing LMDE6 to the Samsung nvme on my triple booted Asus desktop I've had unusual behavior with Grub as well.
The first fresh boot after the LMDE6 installation the Debian 12 , /dev/sda/ installation to my 1 TB HDD and my Slackware 15, /dev/sdb/ install on the WD were switched around.

A few days ago there was a upgrade to the kernel on the LMDE6 install, so I allowed the update for the new kernel and rebooted.
Upon rebooting Debian 12 and Slackware 15 were switched around again.

Yesterday I had to remove old kernels and their headers on my Debian 12 install as the /boot partition was full and there was 0 bytes left of the disk.
Rebooted and updated grub in the LMDE6 installation and shut down for the evening.

The boot order of Debian and Slackware in my Grub Menus has been switched around again!

Before installing LMDE6 this flip flopping of the drives did not occur. Furthermore, there wasn't any other unusual behavior of any kind with Linux Mint 21.1 installed
to the main drive: the Samsung Evo nvme that's set in the BIOS to be the main device.

Anyone have any ideas as to what is going on?

Any assistance is appreciated, thanks in advance.-
Ultimatecat

[oldfred]

I have multiple Kubuntu installs & occasionally something else.
I use this to know what is where. And save report to my backups.

Please copy & paste the pastebin link to the BootInfo summary report ( do not post report), do not run the auto fix till reviewed. Use often updated ppa version with your USB installer or any working install over somewhat older ISO.
https://help.ubuntu.com/community/Boot-Repair &
https://sourceforge.net/p/boot-repair/home/Home/

Typically last install changes boot order so that one is the new default. If you want a different install to be default, you have to change boot order. Often easier to just reinstall grub from preferred install and add a grub entry for newest install. I prefer my own entries in 40_custom over os-prober.

[UltimateCat]

Thanks for the swift reply, Olfred-

I'll have to make a Live USB of 'Boot Repair' as my desktop does not have a cdrom drive.
Will using the dd command work?

When you make your own 40_custom entries is that done in the /etc/default/grub config or in /etc/ftab/?

[UltimateCat]

Here's the Paste Bin link to the output of the boot info. script:

https://pastebin.com/gn2FJyVU

[oldfred]

You show old BIOS boot with both very old MBR (sda) and newer gpt partitioning (sdb & NVMe).

Report not showing anything about Linux partition on NVMe drive. I would expect you would want installs on NVMe drive as that greatly improves performance.

Report also did not show Slackware's fstab, see line 657. Do you have that and report did not show it.
Not sure Boot-Repair has been tested a lot with Slackware.

You show a total of 3 swap partitions. Unless trying to hibernate on 3 different systems, you really only need one swap partition.
But have to make sure a new install does not reformat the unformatted swap and reset its UUID. Then other installs may have issues booting.

I add boot stanzas to /etc/grub.d/40_custom in Ubuntu. I expect Debian to be same, not sure about Slackware.

You have UEFI system, since you have NVMe drive, so bit surprised your installs are old BIOS/MBR.
I started using gpt in 2010 and have not created nor changed a drive to MBR since. But did not start with UEFI until 2014.

Using 40_custom & Custom menu
https://help.ubuntu.com/community/Grub2/CustomMenus
Lots of discussion & examples. May be best to read first page & jump to last page & work backwards for newest examples.
https://ubuntuforums.org/showthread.php?t=2076205

[yancek]

Some curious things I see in your boot repair include Grub version 1.99 installed on both drives? It also shows Grub looking for its files on sda in partition 92 and on sdb in partition 87 which do not exist. What is the vfat partition on sda (sda3)? Was that an EFI partition? It shows a grub.cfg file there. sdb1 is a BIOS Boot partition which is used for a Legacy install on a GPT drive. It shows 2 swap partitions, sdb2 and sdb3. I see the grub.cfg file on sda contains only Debian entries and the grub.cfg file on sdb only Slackware. Were these systems being booted from the BIOS firmware? I see that sdb is shown as a GPT drive but no indication if it is GPT or dos? Lines 106 and 107 show info on the nvme drive but I see nothing else regarding that drive so what is that supposed to be, the LMDE?

[UltimateCat]

Thank you Olfred for the information you explained. I'll go and read about using 40_custom and custom menu and the other link's you posted.
I can delete one of the swap partitions on the Slackware install in Debian with g-parted.
Do I only need one swap partition for all 3 install's?

[UltimateCat]

Thanks for chiming in yancek.
The vfat partition on sda3 is a 300 MiB partition for the /boot/efi.

No, these were not being booted from the BIOS firmware.
The reason why there is a BIOS boot partition is because the Slackware documentation recommended that I do that in order to have Grub instead of LILO for Slackware.

Here are the instructions I followed for my Slackware install on /dev/sdb : the 500 WD HDD.
https://docs.slackware.com/howtos:sl...r_installation

After the message: “Installation of Slackware Linux is complete.

Enter the SHELL then run these cmds.

# chroot /mnt


If you want to use Grub 2, make sure you have a 'BIOS boot partition' (partition type EF02 in gdisk or cgdisk). This can be anywhere on disk though putting it at the start seems sensible. It is recommended that it be at least 1MiB. Skip the bootloader (LILO) section during install. After installation is complete, enter your local Slackware install. Finally, issue the following to actually install Grub 2 as your bootloader:

# grub-install --modules=part_gpt /dev/sda
# grub-mkconfig -o /boot/grub/grub.cfg
#exit
#reboot

Here's informaiton on the nvme: and yes, LMDE6 is installed to the nvme.
[HTMLroot@slackware64:~# fdisk -l
Disk /dev/nvme0n1: 232.89 GiB, 250059350016 bytes, 488397168 sectors
Disk model: Samsung SSD 970 EVO Plus 250GB
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x7edfcd8f

Device Boot Start End Sectors Size Id Type
/dev/nvme0n1p1 4096 17190911 17186816 8.2G 83 Linux
/dev/nvme0n1p2 17192960 488396799 471203840 224.7G 83 Linux
][/HTML]

Should I delete those 2 swaps on my Slackware install?

[oldfred]

It looks like the instructions you followed for Slackware are for the old BIOS install.
Does Slackware even have UEFI install? Found this:
http://docs.slackware.com/howtos:sla..._uefi_hardware

But you may be able to boot UEFI from your install and then create a boot stanza to directly boot Slackware.
I have an UEFI install on an External drive and booted it with my very old (2006) laptop by adding a BIOS boot stanza to directly boot grub in the install. You may be able to reverse that. The only real difference with UEFI & BIOS is the version of grub. The grub in the install is the same.

If you delete swap partition(s), make sure you delete fstab entries first or update swap entry with UUID of the one you keep. Otherwise you may have boot issues.

[UltimateCat]

Output form Slackware:

root@slackware64:~# cat /etc/fstab
/dev/sdb2        swap             swap        defaults         0   0
/dev/sdb3        swap             swap        defaults         0   0
/dev/sdb4        /                ext4        defaults         1   1
#/dev/cdrom      /mnt/cdrom       auto        noauto,owner,ro,comment=x-gvfs-show 0   0
/dev/fd0         /mnt/floppy      auto        noauto,owner     0   0
devpts           /dev/pts         devpts      gid=5,mode=620   0   0
proc             /proc            proc        defaults         0   0
tmpfs            /dev/shm         tmpfs       nosuid,nodev,noexec 0   0
root@slackware64:~# ls /etc/fstab/
/bin/ls: cannot access '/etc/fstab/': Not a directory
root@slackware64:~#

I don't know if Slackware has UEFI install. I'll have to go to the Slackware documentation.

This is a Asus Tuf Gaming mobo and the BIOS are UEFI.
Custom built desktop approx 3 years ago:-

Which fstab entries should I delete?
The ones on LMDE? Debian 12?