When all else fails . . . restore from backup!
Keeping good backups is frequently the only way to recover from some accidents, disasters, or break-ins. Linux has a number of methods for archiving your data, ranging from tools like
cpiothat come with Linux to feature-rich, sophisticated, commercial packages.
There are a number of ways to keep backups, ranging from simply
taring your entire filesystem to a tape to using
dump and a well-designed backup schedule to running high-end commercial backup and restore programs.
Of course, you also have a variety of backup media to choose from: floppies (if you are truly desperate), tape drives (from old nine tracks up to DAT), write once, read many (WORM) drives, magneto-optical ...