Hi, Jan Gregor wrote: > After message about formatting of the media I saw about 10 lines of write > buffer with very high estimate followed by error message > WRITE@LBA Input/output error
So for now the best guess is that the drive does not like the medium. > > Buffer underrun is not an issue with BD-R. > Well, I'm not sure. In my case is default write speed is 6x and my burner > uses USB2 port. I found some posts about recommended speed. The specs say that DVD+R and BD-R can have more than one track open for writing. This implies that the tracks can stand it when writing pauses on the one track, while the other track is being written. > > > the drive should have buffer underrun protection. They all have since years. But it gets into effect only if the burn program sends a data structure called "mode page 05". This is appropriate only for CD and DVD-. The specs say that the drive shall ignore it with any other media type. (They obviously obey, because last time i looked into the -V output of cdrecord, it still sent mode page 05 to DVD+RW.) If the BD-R is formatted and checkreading is not disabled (which growisofs does not do) then the drive will pause with writing after about half of a drive buffer (e.g. 1 MB) and checkread that piece of freshly written data. This reduces effective speed to less than half nominal speed. Especially it would not work if buffer underruns would be an issue. > my burner uses USB2 port. This outrules the USB 3 timeout problems, which seem to happen with some drives and some kernels. Other operating system spacific problems are not known to me currently. > > -speed=1 > I'll definitely check it. If it helps, then it is not about a buffer underrun but rather about the physical quality of the laser and the media dye. (I am still curious why Dominque reduces his drive's speed regularly.) Have a nice day :) Thomas