grub
grub
reset (root) password in grub
in the grub shell:
search --no-floppy --label boot --set=bootp
ls ($bootp)/non-UEFI:
linux ($bootp)/vmlinuz-<TAB-TAB-TAB> root=LABEL=root rootfstype=btrfs rootflags=subvol=@ ro init=/bin/bash
initrd ($bootp)/initrd.img-<TAB-TAB-TAB>
bootUEFI:
linuxefi ($bootp)/vmlinuz-<TAB_COMPLETE> root=LABEL=root rootfstype=btrfs rootflags=subvol=@ ro init=/bin/bash
initrdefi ($bootp)/initrd.img-<TAB_COMPLETE>
bootideally you are in your root shell now:
mount -o remount,rw /
passwd
sync
exec /sbin/reboot -f