MakeMKV as dvdisaster for BDs and UHD BDs and feature request

[woekitten1701]

For months now, whenever I buy new DVDs, I use dvdisaster to do a quick scan of the disc to be reasonably assured that there are no problems with the disc. I first started doing this only with old or used DVDs, but I've taken to just doing it for every one in intake into my collection. I've also been using MakeMKV to do a temporary "backup" of all BDs and UHD BDs that I intake for the same reason, as it's the closest I'm aware of to a complete read of these types of discs where read errors would show themselves. (I do decrypt at the same time, not sure how necessary that is, but I figure better safe than sorry, and if there were any transparent read errors the decryption step would likely raise them.)

This has saved me many times, where I was able to obtain a replacement from a retailer for movies that I probably wouldn't have watched for months after purchasing them. However, it's a little annoying to have to dedicate so much hard drive space to these temporary backups; I delete them right after they're made.

So, I guess this is sort of a feature request. It would be nice if there were some function added to MakeMKV that could accomplish this task without needing to actually write everything it reads to disk. If you've never used dvdisaster, could even be nice to have a graph of read speeds over the course of such a test, or maybe even over the course of a real backup too. I realize this isn't exactly MakeMKV's target functionality, but as it's the best software I'm aware of for reading and decrypting BDs and, particularly with LibreDrive firmware, UHD BDs, I'm not sure where else it could go.

[dcoke22]

Out of curiosity, why not just save the rips and watch things that way? It sounds like you're already doing the laborious part reading all the bits on the optical disc.

[woekitten1701]

Out of curiosity, why not just save the rips and watch things that way? It sounds like you're already doing the laborious part reading all the bits on the optical disc.

I like having my collection of discs on display, in nice cabinets/shelves with glass doors, for browsing and selecting what to watch, and using actual video disc players to play them back, for regular viewing. I separately have a huge >100TB storage array and frankly it stresses me out to manage it and worry about problems with it, and I would need to increase those things considerably to have the capacity to keep my thousands of discs in an online format for basic viewing.

[woekitten1701]

Having tested a few dozen discs since posting this, I'm still very interested in this sort of feature; at minimum, a full disc read "backup" that doesn't actually write any/many files to disk would be fantastic. Thankfully I'm using a HDD as destination, but I did use an SSD occasionally when I was doing three drives at once to ensure maximum throughput for all three instances running simultaneously, and that very quickly killed 1% of the flash's write endurance within just a few days.

[dcoke22]

I have no idea if setting the output to /dev/null (or the Windows equivalent https://stackoverflow.com/questions/313 ... on-windows) will work, but it might.

[woekitten1701]

I have no idea if setting the output to /dev/null (or the Windows equivalent https://stackoverflow.com/questions/313 ... on-windows) will work, but it might.

Since it backs up to a directory, and needs to create subdirectories and a complete file structure, it would not seem likely to work, though admittedly I haven't even tried. I suspect something like this FUSE "nullfs" filesystem might work, as it allows the creation of a directory structure but with every file acting as if /dev/null. That approach would depend on whether makemkv expects to be able to read anything it has recently written out during the backup process. I could trace the makemkv process to see what sort of reads it attempts during a backup, I suppose, but this would all be at best an elaborate solution to something that likely makes more sense as a feature in the software itself.