My system won't boot, what can I do from rescue mode to repair my system?

In repair mode, there is no single command that we can recommend to run that will fix the issue because the boot failure can be caused by many different things.

If you suspect file system corruption, the e2fsck command can be useful to repair a corrupted file system. A command like e2fsck /dev/device_name can be run from repair mode to check and repair a file s...