Success, at last! I burnt a couple of BD-R discs, on Monday, using a USB 2 card, fitted into the problem PC, as the source external HD connection, and the rate was roughly 22 GiB in half an hour.
Here's the tail end of the output: xorriso : UPDATE : 22408 of 22530 MB written (fifo 98%) [buf 96%] 3.3x. xorriso : UPDATE : 22421 of 22530 MB written (fifo 99%) [buf 96%] 3.1x. xorriso : UPDATE : 22435 of 22530 MB written (fifo 99%) [buf 96%] 3.2x. xorriso : UPDATE : 22449 of 22530 MB written (fifo 99%) [buf 96%] 3.3x. xorriso : UPDATE : 22463 of 22530 MB written (fifo 98%) [buf 96%] 3.3x. xorriso : UPDATE : 22477 of 22530 MB written (fifo 83%) [buf 96%] 3.1x. xorriso : UPDATE : 22490 of 22530 MB written (fifo 62%) [buf 90%] 3.1x. xorriso : UPDATE : 22505 of 22530 MB written (fifo 39%) [buf 96%] 3.3x. xorriso : UPDATE : 22519 of 22530 MB written (fifo 17%) [buf 96%] 3.3x. xorriso : UPDATE : 22530 of 22530 MB written (fifo 0%) [buf 100%] 2.6x. xorriso : UPDATE : Closing track/session. Working since 1732 seconds xorriso : UPDATE : Closing track/session. Working since 1733 seconds Writing to '/dev/sr0' completed successfully. xorriso : NOTE : Re-assessing -outdev '/dev/sr0' Drive current: -outdev '/dev/sr0' Media current: BD-R sequential recording Media status : is written , is appendable Media summary: 1 session, 11535712 data blocks, 22.0g data, 567m free The big difference, of course, is the fifo being loaded to 90-something percent through most of the writing. So, I have no evidence that this was a libburn bug. Everything points to my problem's cause being inappropriate hardware (namely, a USB 1.x interface in the path to the ISO file). Additional detail: Cdrecord 2.01-Emulation Copyright (C) 2013 see libburnia-project.org xorriso xorriso 1.3.2 ISO 9660 Rock Ridge filesystem manipulator and CD/DVD/BD burn program Copyright (C) 2013, Thomas Schmitt <scdbac...@gmx.net>, libburnia project. xorriso version : 1.3.2 Version timestamp : 2013.08.07.110001 Build timestamp : -none-given- libisofs in use : 1.3.8 (min. 1.3.6) libjte in use : 1.0.0 (min. 1.0.0) libburn in use : 1.3.8 (min. 1.3.4) libburn OS adapter: internal GNU/Linux SG_IO adapter sg-linux libisoburn in use : 1.3.2 (min. 1.3.2) Provided under GNU GPL version 2 or later. There is NO WARRANTY, to the extent permitted by law. $ dvd+rw-mediainfo /dev/sr0 INQUIRY: [PIONEER ][BD-RW BDR-209M][1.20] GET [CURRENT] CONFIGURATION: Mounted Media: 41h, BD-R SRM Media ID: CMCMAG/BA5 Current Write Speed: 8.0x4495=35960KB/s Write Speed #0: 8.0x4495=35960KB/s Write Speed #1: 6.0x4495=26970KB/s Write Speed #2: 4.0x4495=17980KB/s Write Speed #3: 2.0x4495=8990KB/s Speed Descriptor#0: 00/11826175 R@8.0x4495=35960KB/s W@8.0x4495=35960KB/s Speed Descriptor#1: 00/11826175 R@6.0x4495=26970KB/s W@6.0x4495=26970KB/s Speed Descriptor#2: 00/11826175 R@4.0x4495=17980KB/s W@4.0x4495=17980KB/s Speed Descriptor#3: 00/11826175 R@2.0x4495=8990KB/s W@2.0x4495=8990KB/s READ DISC INFORMATION: Disc status: appendable Number of Sessions: 2 State of Last Session: empty "Next" Track: 2 Number of Tracks: 2 READ TRACK INFORMATION[#1]: Track State: partial incremental Track Start Address: 0*2KB Free Blocks: 0*2KB Track Size: 11535712*2KB Last Recorded Address: 11535711*2KB READ TRACK INFORMATION[#2]: Track State: invisible incremental Track Start Address: 11535712*2KB Next Writable Address: 11535712*2KB Free Blocks: 290464*2KB Track Size: 290464*2KB FABRICATED TOC: Track#1 : 14@0 Track#AA : 14@11535712 Multi-session Info: #1@0 READ CAPACITY: 11535712*2048=23625138176 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1458230 Title: libburn imposing 0.2x BD-R burn (5-6 hours) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libburn/+bug/1458230/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
