[OpenSUSE Tumbleweed] Stuck in a writable snapshot that eats up all my system disc space

Note: I added more info in the OP

geteilt von: https://discuss.tchncs.de/post/52933193 (OP)

A few days ago I noticed, that my system disc (~120gb) is almost maxed out. Since almost everything that takes up considerable disc space resides on my 2 discs, I started investigating, supported by ChatGPT. Turns out I've been running on a writable snapshot that keeps growing with each update. Again, important stuff is on my other discs, so reinstalling Linux allover would be a inconvenience, but no problem. Yet, I'd like to try repairing current installation, if only for the lessons learned.

I let ChatGPT summarize everything as a post so you don't have to deal with my half-educated gibberish:

du -xh --max-depth=1 / only shows ~16 GB used, but df -h reports ~113 GB used. Root, /var, /usr, /home, etc. are all on the same Btrfs filesystem. Snapper is enabled.

I confirmed that Btrfs snapshots are consuming the space, but I’m stuck with a writable snapshot (#835) that is currently mounted, so I can’t delete it from the running system.

To make things worse:

GRUB menu does not appear (Shift/Esc does nothing)

The system still boots into Linux, but I can’t select older snapshots

I tried repairing from an Ubuntu live USB, but:

NVMe device names differ from the installed system

Chroot fails with /bin/bash or /usr/bin/env not found

Likely because /usr is a separate Btrfs subvolume and not mounted

At this point I’m trying to:

Properly mount all Btrfs subvolumes from a live system

Chroot into the installed system

Delete old Snapper snapshots

Reinstall GRUB so the menu works again

If anyone has step-by-step guidance for recovering openSUSE Tumbleweed with Btrfs snapshots and broken GRUB access, I’d really appreciate it. I’m comfortable with the command line but want to avoid making things worse.

Hope someone can make something of it and help me fix my system.