After updating my Tumbleweed system to latest version 20260430 (Kernel 7.0.2-1-default) by “zypper dup”, my system did not boot any more. I am almost sure that with kernel 7.0.1 booting was fine.
Error: /sysroot could not be mounted. Error message in dracut shell like “cannot mount /sysroot - unknown parameter subvol for ext4 fs”.
Root cause: Some update script added “rootflags=subvol=/.snapshots//snapshot” to the boot entry in “/boot/efi/loader/entries/system-opensuse-tumbleweed-*”
Workaround: Remove the rootflags parameter in grub before booting.
Reproducable: When using the Bootloader app in yast, the rootflags parameter is added again.
I use:
- ext4 filesystem on root and boot partition (not encrypted)
- Bootloader: Grub2-bls
- no secure boot
Additional info/findings:
a) It seems that the default boot entry was not updated to latest kernel.
b) The boot entries for already removed kernels were not removed by update process. I had to run “sdbootutil cleanup” manually to get rid of all the outdated entries.