This is an automated archive made by the Lemmit Bot.

The original was posted on /r/datahoarder by /u/manzurfahim on 2025-12-03 09:01:20+00:00.

I have had 3-4 instances of bit rot, where the file just got corrupt. No issues with the drives, not bad blocks, no unexpected shutdowns or crashes, but suddenly the files were corrupted. RAW files had pink-grey glitches, two of the video files had frame glitches etc. It made me think: what can I do to prevent this?

Files on my RAID6 is safe, the controller can do consistency checks and if anything does not match with the initial stripes, it fixes them. The problems that I had happened on offline drives, where I off-load files from RAID array.

So, this is what I started doing:

  1. I use WinRAR to archive the files. I password-protect files that are sensitive, otherwise I just archive them. WinRAR uses AES 256 encryption, so it is pretty safe. I split the archives in 1GB or 2GB files.
  2. I use a certain percentage of recovery record, depending on how important the files are. For example, If I set a 10% recovery record, it means if an archive file gets corrupted, and if the corruption is below 10%, it can repair itself. Yes, it also means, the archive size gets 10% bigger (10% of the total archive size after compression), but the files are safe.
  3. I also add recovery volume. For example, if I add five recovery volumes, and if five of the archive files goes missing, or damaged beyond repair, the recovery volumes then act as parity and can reconstruct the missing files. Each recovery volumes are almost the same size as the archive files, so if the archive files are 1GB in size, and if I add five recovery volumes, each of the recovery volumes will be 1GB.
  4. Once I archive the files, I test the archive. I use the built-in test feature, and I also extract them to another location, and hash-check it with Quick Hash against the source files to make sure they match.
  5. Once it is ready to be offloaded, I move them to two drives, and when done, I disconnect the drives.

Most of my files are photos, so even after setting up a 10-20% recovery record and 5-10 recovery volumes, the archives are still smaller than the original files. So, I’m saving space, protecting them against bit rot, and I have them encrypted and password protected.