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(a)3.3x1385=4584KB/s W(a)8.0x1385=11080KB/s
Speed Descriptor#1: 02/2295103 R(a)3.3x1385=4584KB/s W(a)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