Hi, i got an SCSI log of a failed burn run from Michael Lange.
No artsy dance between drive and libburn is to see, which could explain a misunderstanding between both. The drive buffer becomes full, after 17 seconds some few sectors seem to have been actually written, and then the second next WRITE(10) fails with the "illegal request" error. Its data would not fit into the buffer, but the drive does not wait until there is room. So it has something to do with a full drive buffer. ------------------------------------------------------------------------- cdrskin can avoid to fill the buffer by an old workaround from the bad old days of parallel ATA controllers when the CD burner blocked the hard disk on the same controller while a WRITE(10) was waiting for buffer space in the burner. I wonder whether this workaround can avoid the drive's error reply. If you are curious enough, add to your cdrskin runs this non-cdrecord option modesty_on_drive=1:min_percent=75:max_percent=80 It will pause sending of data when the drive buffer is in danger to become more than 80 percent full. Sending data is resumed when it is below 75 percent full. (Ye olde cdrecord option -immed is in cdrskin implemented as modesty_on_drive=1:min_percent=75:max_percent=95 but for this experiment we should give more free room than 5 percent.) ------------------------------------------------------------------------- Long story of the SCSI log: The reported drive buffer capacity is not 2 MiB but 1,179,648 bytes. All looks well until LBA 416 is written. The most recent buffer inquiry showed 98304 bytes free. Three more WRITE(10) succeeded which added 91728. So the buffer might be full up to 6576 free bytes. The WRITE(10) to LBA 416 brings 30576 more bytes. Now happens nothing for 17 seconds. Then the pending WRITE(10) command gets a "no problem" reply. The subsequent WRITE(10) command for LBA 429 ends swiftly without error reply. Inquiry of the drive buffer reveils 10240 free bytes. The next WRITE(10) goes to LBA 442 and gets an immediate error reply of Key 5, ASC A8, ASCQ 04. (As said, ASC A8 is not listed in my copies of SCSI specifications.) libburn takes this as fatal error and brings the burn run to an emergency halt. The drive needs 110 seconds until it replies success to a TEST UNIT READY command. That would suffice for the whole 168 MB of payload at the chosen speed of 10x (= 750 sectors/second). During that time, the TEST UNIT READYs got replied Key 2, ASC 04, ASCQ 07 which means "Logical unit not ready, operation in progress". 4 seconds later, the CD is ejected and the cdrskin run ends. ------------------------------------------------------------------------- Have a nice day :) Thomas