SystemRescue

SystemRescue has served as a go-to 'break glass in case of emergency' toolkit for over two decades: a bootable live image carrying partitioning tools (GParted included), file system repair utilities for both Linux and Windows/NTFS volumes, disk-cloning and backup tools, and password-reset utilities, aimed at recovering a system that won't boot or has a failing drive. Rebased onto Arch Linux, it stays current with modern hardware and filesystem support (including Btrfs and ZFS) far better than an old, infrequently-updated rescue disk would. It's a standard recommendation across the Linux community specifically as the tool to reach for when a system is broken badly enough that its own normal boot process can't be trusted.