Hi list, I have massive performance problems when using the standard approach via an udf file system. The disk spins up and down all the time, reducing my write speed to about 800k/s. My disk cache is maxed out and 'sync'ing takes ages. I see this with and without the pktcdvd driver with DVD+RW and DVD-RAM media. The classical mkisofs route works as expected. Feeding the packet driver with 4k blocks (mbuffer -s 4096) results in the full advertised 8x DVD writing speed: tar -cvM -L4500000 -f - /mnt/data/backup/debian-2005-02-06.tar.gz /mnt/data/backup/snapshots/daily.0/ | mbuffer -m 1000k -s4096 -P 10 > /dev/pktcdvd/dvdrw Without the -s 4096 option I get the same low performance behavior. I also tried different buffer sizes in the kernel module and the experimental write caching. What's wrong and how can I help improving the packet driver? Thank you very much! Johannes Nieß stingray ~ # dvd+rw-mediainfo /dev/hdc INQUIRY: [HL-DT-ST][DVDRAM GSA-4163B][A106] GET [CURRENT] CONFIGURATION: Mounted Media: 1Ah, DVD+RW Current Write Speed: 8.0x1385=11080KB/s Write Speed #0: 8.0x1385=11080KB/s Write Speed #1: 6.0x1385=8310KB/s GET [CURRENT] PERFORMANCE: Write Performance: 6.0x1385=8310KB/s@[0 -> 112639] 8.0x1385=11080KB/s@[112640 -> 2295103] Speed Descriptor#0: 02/2295103 R@3.3x1385=4584KB/s W@8.0x1385=11080KB/s Speed Descriptor#1: 02/2295103 R@3.3x1385=4584KB/s W@6.0x1385=8310KB/s READ DVD STRUCTURE[#0h]: Media Book Type: 00h, DVD-ROM book [revision 0] Media ID: RICOHJPN/W21 Legacy lead-out at: 2295104*2KB=4700372992 READ DISC INFORMATION: Disc status: complete Number of Sessions: 1 State of Last Session: complete Number of Tracks: 1 BG Format Status: suspended READ FORMAT CAPACITIES: formatted: 2295104*2048=4700372992 26h(0): 2295104*2048=4700372992 READ TRACK INFORMATION[#1]: Track State: complete Track Start Address: 0*2KB Free Blocks: 0*2KB Track Size: 2295104*2KB FABRICATED TOC: Track#1 : 14@0 Track#AA : 14@2295104 Multi-session Info: #1@0 READ CAPACITY: 2295104*2048=4700372992 niess@stingray /tmp $ uname -a Linux stingray 2.6.19 #6 PREEMPT Fri Dec 1 22:43:51 CET 2006 i686 Intel(R) Pentium(R) 4 CPU 2.40GHz GNU/Linux