Strange mkisofs crashes when burning BDXL with k3b

I have a Blu-Ray burner and my main use for it these days is an annual backup of my own data to M-Discs (which are marketed to last really long). I’m burning with k3b. I’ve had problems that something stops in the process, failing to backup and apparently ruining the disc in the process (and they are really expensive, so it matters).

I have burned many disks successfully, but I ran into problems last year and today. I have pasted the debug log in here and relevant dmesg here. Out of this, the line that seems most significant to me is this:

:-[ WRITE@LBA=8ceac0h failed with SK=3h/WRITE ERROR]: Input/output error


[4554733.284132] sr 4:0:0:0: ioctl_internal_command: ILLEGAL REQUEST asc=0x53 ascq=0x2

Any idea what goes wrong here?

That error message comes from growisofs (part of dvd+rw-tools), not mkisofs. From a quick Google search: it’s not a crash, but it could be a disc failure.

Right, it was k3b that reported it as a mkisofs crash. Yeah, you’re right, these are two different things, so that only added to the confusion.

I could be seeing subtly different things, but these discs are brand new, top-of-the-line discs, so a disc failure would be strange…