dvdisaster VS MultiPar

DVDisaster, https://github.com/speed47/dvdisaster

My family has a collection of important pictures, documents, and videos which are currently stored on CD-R, and have been since 2005. Ten out of the ~250 discs have been destroyed by disc rot, but luckily there were redundant copies. I am planning on migrating the collection to BD-R, because they seem much more robust. I'm also going to use ECC to protect the discs (https://github.com/speed47/dvdisaster)

For my optical backups I use this additional software, called DVDisaster. I create image with 10 to 15 % space left and let the program augment the image with recovery data. After that's done, I burn it to optical media.

dvdisaster

dvdisaster has returned to life too.

I hope you use dvdisaster to protect your data. If you use it on an ISO before burning it, you can make a bit-exact recovery in most cases, even discarding the zero padding introduced sometimes on re-ripping the disc and mangling things.

Even with archive-grade media you should use something like dvdisaster to generate error-correction-code (ECC) files for each disk (rule-of-thumb, 20% of each disk should be filled with ECC data. That only leaves you with 80 GB if you are using 100 GB BDXL M DISCs)

https://github.com/speed47/dvdisaster (there's tutorials to show you how this works all over youtube and the internet and the manual)

but... depending on how much effort you want to spend fixing it I might be able to fix your current corrupt files, especially if the corrupt files are only mildly corrupt I could create a '.par2' file from mine (assuming you are on build 1436.28), then you would use MultiPar (i.e. https://github.com/Yutaka-Sawada/MultiPar/releases ) to scan your files and it will tell me how many blocks you need to fix it and then I could create recovery data with MultiPar. doing this might dramatically lower the amount of data I would have to upload as then you could use MultiPar which will fix your current corrupt files so they match mine identically.

MultiPar is the continuation for Windows https://github.com/Yutaka-Sawada/MultiPar

And this for Linux https://github.com/animetosho/par2cmdline-turbo

* MultiPar supports in-situ repair, which bypasses this problem entirely

To detect bitrot I use dynamix file integrity plugin, it compute Blake3 hash for each file, it is stored as extend attribute. You Can choose which share will be covered. For correction i then use par2 files using multipar https://hp.vector.co.jp/authors/VA021385/ https://github.com/Yutaka-Sawada/MultiPar (Windows only, par2cmdline for Linux. You could compile from source and add it to unraid if you want, i've done it for testing purpose)

And last but not less important - make regular parity files of your healthy important data, and store them somewhere. MultiPar is your best friend. Even if your data gets corrupt, with parity files you can restore it to it's former glory. Some limitations will apply, read the manual.

This is possible with MultiPar https://github.com/Yutaka-Sawada/MultiPar

More sanely, perhaps, get some M-Disc DVDs (if you can find real ones - apparently they're becoming just normal DVDs) and put one file on each, and then run https://github.com/Yutaka-Sawada/MultiPar on it to create parity files. Then store the file, the parity files, and the software you need (MultiPar) on the disc. To be safe, you probably also need to store the DVD burner you used to make it, as those are getting thin on the ground these days.

Note about par2: if one is using a windows system with a nvidia GPU this version of par2 is faster as it speaks CUDA.

For any file repairs use multipar, it's still being updated and has gpu acceleration. https://github.com/Yutaka-Sawada/MultiPar/releases