rollback
also: revert, downgrade
The process of reverting a system or application to a previous state, typically after an update or change fails or causes problems.
A rollback is the act of undoing recent changes and restoring a system to an earlier, known-good state. This is commonly used when a software update breaks functionality, introduces bugs, or degrades performance.
Rollbacks are essential for system reliability. For example, if you update the kernel and the system fails to boot, you can rollback to the previous kernel version using your bootloader. Similarly, package managers like apt or dnf may support rolling back package upgrades, and container systems like Docker can roll back to previous image versions.
Some systems implement rollback through snapshots or version control, allowing quick recovery. Filesystems like Btrfs and ZFS support snapshots that enable point-in-time rollbacks. Without proper rollback mechanisms, failed updates can leave a system in an unrecoverable state.