Split large backup on multiple disks while still being able to use each disk individually

Question

I'm intending to back up my photo collection to Blu-ray media(1). The collection is about 840 GB, but no individual file is larger than one Blu-ray disk.

In the past, what I have usually done is to compress everything into a large file split into volumes - but if I do that I will not be able to do anything with each volume unless I have all of them. This will be useful if any of the disks ever go bad during storage.

Here is an example where i have compressed (althoug without any compression) the whole collection with 7zip:

So what I am asking is if there is an easy way to either compress everything into individual files, or otherwise split everything into "volumes" that will fit the chosen media, without requiring all volumes to be present.

(1) I'm already backing everything up online, the backup on optical media will be placed in a bank vault on a yearly+ basis.

Answer 1

You already got answer how to do that on unix base systems. Here how you can do that under Windows:

You can use Folder Axe` to split your files by folders that will be filled by specified size.

Another solution is to install cygwin - "native" unix on windows (not a virtual environment but native executables) and genisoimage package. This way you can use dirsplit mentioned by @Kamil Maciorowski

I don't think that compressing media files in your case is a good idea since most of them are already compressed.

BTW, long term keeping information isn't a simple task as it sounds. Technology going forward pretty fast, so a storage you going to use could be hard to restore over time if you don't have the same hardware that exist on a moment of creation (Floppy drives for example, it is a challenge to find now 5" floppy drives). Besides, quality of storage such as CD/DVD/Blu-ray are degraded over time. You should use a special "Archival Grade" (golden) disks for long term storage. As about me, I found that the cheapest and most important - more reliable way to keep information that need to be stored for a long time - it is a simple hard drive. I have HDDs that keeping information that was written 25 years ago and all files are still good on them, that is what I can't say about CDs, many of them non readable even they in a perfect shape.