Grub 2.16 remembers "fallback"-entry too

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1

Grub 2.16 installed.
On reboot the old behavior jumping from fallback to default does not work any longer…
/etc/default/grub contains:

GRUB_DEFAULT=saved
GRUB_SAVEDEFAULT=true
2

As I understand it — I’m on the Stable branch, so I don’t have 2.16 yet — the new grub now has write support for btrfs, which means that with the settings you’ve included above, grub will indeed now remember that you booted the “fallback” entry, and will select that upon the next boot unless manually overridden.

This is actually how it has always worked, but due to btrfs having become the default filesystem in Manjaro, this functionality was hitherto broken unless one had /boot on an ext4 volume.

3

Hope, anybody knows, how “fallback” was excluded from “remember”-function??
(in and before 2.14)

4

see this [Unstable Update] September 2026 - #63 by Yochanan

GRUB_DISABLE_OS_PROBER=true            --> other boot & disks         -- false
GRUB_DISABLE_UEFI_FIRMWARE=false       --> UEFI fallback              -- false
GRUB_DISABLE_BOOTNEXT=true             --> others linux on same disks -- false
5

Pretty sure you are talking about different fallbacks.
What GaVenga means is the initramfs made by mkinitcpio.

No idea how to exclude that, but me personally i have disabled it. It makes no sense if one has a usb live image.

6

It wasn’t, but grub could not write to btrfs until now, and therefore, it could not save the last-booted entry, causing the default entry to always be the kernel with the highest version number, and with its normal initramfs.

Of course, for people with ext4 for their root filesystem and people with a separate ext4 partition for /boot (even if the root filesystem is btrfs or xfs), this problem never even existed.

It was strictly a grub problem. grub could reliably write to ext2, ext3, ext4 and anything FAT-based, but with other filesystem types, it was hit-and-miss. Even its read support for btrfs was severely restricted, because it couldn’t read sparse files, and xfs might have been supported in one grub version but then again no longer in another version.

7

That is correct.

Excellent explanation!

  • In 2.16, GRUB gained reliable write support for more filesystems (notably btrfs), so it can finally do what it was always supposed to do: persist the last choice, even if that choice is your fallback kernel.

So your previous “wanted action” (fallback → next boot = normal default) was actually a side‑effect of GRUB not being able to save the fallback entry.

Once upon a time I read, if you start win$ by chainloader,
you have to add savedefault Paramter to this (example) 40_custom
in /etc/grub.d/…
otherwise win$ doesn’t perform a proper restart.

I’m a little overwhelmed by this article:
Booting fallback systems - GNU GRUB Manual 0.97
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
This is of /boot/grub.conf:

### BEGIN /etc/grub.d/10_linux ###
........
menuentry ' Manjaro Linux , with Linux 6.18-x86_64 (fallback initramfs)' --class manjaro --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.18-x86_64-fallback-xxxxxxx' {
	savedefault      <===== this line should be omitted, but HOW??
		load_video
.........
### END /etc/grub.d/10_linux ###
...

@stephane

Already made, thanks. :face_with_tongue:

Told problem to devil-opers:
 `https://gitlab.freedesktop.org/gnu-grub/grub/-/work_items/95`