When I performed a routine backup from my hard drive to an external drive which had existing files on it, I found that the backup had deleted all the individual files on that external drive. The folders are still there but there are no files in them.
So now I have lost years of data.
I'm confused. Please clarify.
WHAT backup software program/product did you run which did that "routine backup"? By "routine", that must mean you've been running it regularly and periodically for a while now. So this is the first time you noticed any anomaly at all??
Is this a pure COPY (of all folders/files from source to target), where you end up with a true uncompressed duplicate of the source folders/files on the target drive?
Or is this a BACKUP of some type (e.g. using ZIP or other proprietary compression method) so that you end up with a single "backup dataset" on the external drive which you then need to use the same program in RESTORE mode to selectively recover individual folders/files within the "backup dataset"?
You say that the backup "deleted all the individual files on that external drive"? The folders are now there, but there are no individual files in them. Again, are you using a true COPY as your "routine backup" method, so that the target backup is supposedly an uncompressed exact duplicate of the source? Or are you running a software product that does your "routine backup" probably involving some compression to a single target backup dataset, and from which you must then use the same software product to RESTORE/RECOVER selected folders/files from??
How/why did you first notice that the files on the external drive had "disappeared"? Did you go there to try and use them to restore from, and noticed they were not present although the folder structure was present?? Seems impossible, but that's how I read your description. Are you looking inside a backup dataset using backup software, and seeing that there are no files? I'm confused.
No matter what happened on the output target of the backup, why should anything have been touched or lost on the original INPUT source??? So are you saying that the backup job deleted files from the source as well as deleting files from the target, now making it impossible to recover this data at all? Why can't you just use your original source files, no matter what happened on the target output of whatever type of backup job you "routinely run"?
Please provide a reasonable simple but precise description of what this "routine backup" job consists of. What software program are you using? What is the method of backup... COPY, or BACKUP (of some type)? Any compression involved?
And why should your source data going into any type of COPY/BACKUP get lost, no matter what the output does or does not look like? How could you have lost ALL of your data (both input and output) when you are describing a problem with your output??