Grub defaults to 'saved_entry' after update

[rexxvaldis]

I added a new and bigger HDD to my Tri-boot (Manjaro, Linuxmint and Windows10) system recently, which is used to store media and backup files. I want my system to boot into Manjaro as the default OS. However after Manjaro has a kernel update this changes. If I boot into any of the other OS on startup, when I shutdown the PC, the next time the PC is switch-on it boots to the last used OS.
How can I stop this from happening, such that it always boot the default OS (Manjaro) without having to make this change manually.
What I have to do everytime this happens, I would edit the grub.cfg file and make a change from this

if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="${saved_entry}"
fi

to

if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="0"
fi

[linux-aarhus]

You will have to apply the change to both Linux installations as the active grub will vary depending on which one you started last time.

Change both /etc/default/grub and

• disable the option to save the last used entry
• set timeout-style to menu
• set a reasonable timeout
• disable submenu

#GRUB_DEFAULT=saved
GRUB_TIMEOUT=15
GRUB_TIMEOUT_STYLE=menu
GRUB_SAVEDEFAULT=false
GRUB_DISABLE_SUBMENU=true

Update grub in both systems

sudo grub-mkconfig -o /boot/grub/grub.cfg

Another option could be to distinctively select your Manjaro EFI partition as the primary EFI partition - (done in system firmware or using efibootmgr) - and hope the other Linux don’t change it

Of sourse the above is only valid if you are using EFI cause if you are using MBR then your grub is written to the primary disk defined in BIOS - and you will have nothing but trouble.

[Nachlese]

normally, you only make changes to
/etc/default/grub
and then run
update-grub
or
grub-mkconfig ....
this will re-generate the file that you edited

ps:
see what @linux-aarhus said while I was replying

[rexxvaldis]

I would make those changes…
PS what should i use to wrap the text in for correct formatting.

Sorry I over wrote your formatting of my entry

[linux-aarhus]

I suggest you modify the grub as I described - start with your Mint installation - and generate grub.cfg - then proceed to reboot your system - loading Manjaro - then doing the same.

[rexxvaldis]

This is the linuxmint /etc/default/grub file current entry

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=lsb_release -i -s 2> /dev/null || echo Debian
GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash”
GRUB_CMDLINE_LINUX=""

[rexxvaldis]

I have made the changes to the grub file and it works perfectly. Now it always default to Manjaro at boot-up

I guess this file will change only on re-install of manjaro.

Thank you for your help.