I have a similar issue with Garuda (based on Arch) and OpenSuse Tumbleweed, both of which have root on a BTRFS subvolume. I've done a bit of searching and came to the conclusion that Debian GRUB doesn't detect the OS inside the subvolume. I even tried a custom GRUB config loading the btrfs module, to no avail.
I gave up and use rEFInd on the rare occasions I wish to boot those OSs.
Is your Arch on btrfs?
If anyone has a solution to boot these from Debian GRUB I would be most interested. Was considering starting a topic myself but it's low priority so far.![Mr. Green :mrgreen:]()
Also could you post your custom grub config?
I gave up and use rEFInd on the rare occasions I wish to boot those OSs.
Is your Arch on btrfs?
If anyone has a solution to boot these from Debian GRUB I would be most interested. Was considering starting a topic myself but it's low priority so far.

Also could you post your custom grub config?
Statistics: Posted by sunrat — 2024-05-03 02:08