Hi, meanwhile i am on Debian 8.1, kernel 3.16 and suffer from the described problems myself.
The behavior resembles old IDE master-slave concurrency problems. (Disk at /dev/hdc, burner at /dev/hdd.) There is a coarse workaround from those old times. cdrecord introduced options -immed and minbuf=, which keep the drive buffer hungry and so avoid that the kernel has to wait with a pending WRITE command until the buffer has enough room. growisofs does not have it, xorriso development just got it, but cdrskin has it since quite a while. This allows me to burn with 4x DVD+RW speed, 2.3x BD-RE speed, and 2.0x BD-RE speed simultaneously (about 24 MB/s in total): cdrskin -v dev=/dev/sr1 minbuf=65 filename.iso cdrskin -v dev=/dev/sr2 minbuf=65 filename.iso cdrskin -v dev=/dev/sr4 minbuf=65 filename.iso Burners are LG GH24NSC0 (SATA), LG GGW-H20L (USB-SATA), LG BH16NS40 (USB-SATA). Mainboard ASUS P9D WS. 3.4 GHz Xeon. It does not work well with BD-RE on Optiarc BD-5300S when Defect Management is disabled. In this case the burner seems to wait for a full buffer, while libburn waits for half-empty buffer. After a few seconds the burner empties the buffer and the next write-and-wait cycle begins. Have a nice day :) Thomas -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
