The summary.
DELETION REMOVES THE REFERENCE, NOT THE DATA
Which is why deleted files are frequently recoverable, and why disposal requires more than deleting.
When a file is lost, stop using the drive immediately. Continued use overwrites it.
FOR A FAILING DRIVE, IMAGE IT BEFORE ATTEMPTING RECOVERY
So attempts work on a copy rather than a deteriorating original.
A SYNCHRONISED FOLDER AND A DRIVE ARRAY ARE NOT BACKUPS
A backup is a separate copy from a point in time that the live system cannot alter.
Keep several copies, on more than one medium, with one held elsewhere and one separated from the live system.
Test the restore, and measure how long a full one takes.
USE GROUPS FOR SHARED STORAGE PERMISSIONS, NEVER INDIVIDUALS
Individual permissions accumulate and are never removed.
RELATIVE PATHS MEAN DIFFERENT THINGS FROM DIFFERENT LOCATIONS
Which is why scripts work when run from one place and fail from another.
Case sensitivity differs between systems, and produces failures nobody diagnoses quickly.
