Multi-Disc Ripping with Mac OS X

[JustSomeGuy]

I picked up an LG USB drive and it worked fine when run by itself. I enabled 'ask for single drive mode' and then attempted to burn two discs from a popular Sci-fi series, popular in the 80s and 90s. I ran one instance per drive and saved the files to unique file paths.

On about 90% of the rips (while ripping the whole disc in each MakeMKV instance), I would get errors about failing save file X.

The curious thing, is that the errors would appear in both instance consoles, for the same file at the same time.

I tried enabling expert mode and creating unique file names (copy and paste label from disc to each track) and the error rate dropped down to about 20%.

I then reran one of the discs through both drives and there were no issues with saving the files, all files saved on the first try.

Has anyone else successfully used multiple usb drives on Mac OS X? Is there any tricks or tips? Thanks!

[dcoke22]

I sometimes rip up to 3 discs at a time on macOS Monterey (on Intel). All are connected via USB (I think all into the same USB hub actually) and when I rip, all the files end up at unique paths but on the same volume (a high speed SSD RAID). I almost always am just making decrypted backups since my workflow is disc -> backup -> individual .mkv files.

Sometimes various discs have difficulties, of course, but I've never seen one failure interfere with any of the others.

[JustSomeGuy]

Thanks for the info. I am on an older version, Sierra, so maybe that has something to do with it.

My initial thought, is that there is some shared data that is getting corrupted by the multiple MKV processes.

[dcoke22]

How are your drives powered?

A thing that can happen to people who have USB powered drives is MakeMKV spins them fast enough to push their power needs beyond the power available and they reset, which causes a cascade of failures in the MakeMKV log. I wonder in your scenario if a different, but similar thing is happening? Could one drive stumble over a defect of some kind on a disc and use slightly more power attempting to do a reread thereby causing the other drive to not get enough power. The second drive would appear to get a failure at the same time as the first drive.

I'm just speculating since I have no idea how your drives are powered or connected to your Mac.

In my case, my three drives are full sized drives in external enclosures. Each enclosure has its own power supply and the USB connection is just used for data, not power.

As a side note, if you really are on Sierra (macOS 10.12), can I ask why? High Sierra (macOS 10.13) supports the same minimum hardware and is, obviously, one whole OS revision newer. And it isn't yet over the 32-bit cliff.

[JustSomeGuy]

I have two drives, an apple superdisk plugged directly into the back of the mac, and an LG plugged into a powered usb hub. I did not have debug on when I had the failures, so I am not sure if extra info was there. Are you happy with the drives? What brand/model are they?

I am on Sierra, because I am super paranoid + lazy. Been a lifelong apple owner, but have had some frustrating experiences with OS upgrades (nuts to OS 9) and drive failures (not related, just in general). So, I have stuck on 10.12 because it is stable and because I do not want to spend time rebuilding my machine if the upgrade goes sideways. Like, intellectually I know that is a super small possibility, but ... ya.

[dcoke22]

I have an LG WH16NS60, an ASUS BW-16D1HT, and a Pioneer BDR-212UBK. The LG is my oldest drive. Both the LG and the ASUS are from before supply chains got weird during and after the pandemic. The drive sellers on this forum have suggested the quality of these drives now is lower than it used to be. The Pioneer is my newest drive which I picked up shortly after MakeMKV starting supporting Pioneer drives.

I am generally happy with these drives. If I have a troublesome disc, usually one of the drives can eventually get a clean read. Having multiple drives makes it faster to ingest a multi-disc TV show which is occasionally handy.