Complete procedures with a way back.

Recover a non-booting Ubuntu Server by choosing the least invasive systemd target, preserving console evidence, identifying the failed boot dependency, applying a reversible correction, and proving a clean normal boot.

Copy an Ubuntu root filesystem to a larger ext4 disk, preserve Linux metadata, rebuild UUID-based boot artifacts, perform a controlled cutover, and retain the original disk as a tested rollback.

The mount error “wrong fs type, bad option, bad superblock” is a summary, not a diagnosis of corruption. Identify the exact storage layer, read the kernel reason, and separate missing helpers or invalid options from real damage before configuring UUID-based systemd mounts.