Re: Help with DVD+RW w/UDF file system
Chris Oxenreider wrote:
That seems to isolate the problem to the handling of UDF rather than at
the driver level. I have to go back and reread your OP and see what
kernel, etc, you are using. I don't remember other reporting this issue,
but I don't use UDF normally, so it's not something I can quickly test.
I set the drives parameters to:
hdparm -d1 -k1 -p4 -c1 /dev/hda
The doccumentation for the drive lists it as PIO mode 4 and DMA mode 2.
The listing of the parameters shows:
hdparm -v /dev/hda
HDIO_GET_MULTCOUNT failed: Invalid argument
IO_support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 1 (on)
readonly = 0 (off)
readahead = 256 (on)
HDIO_GETGEO failed: Invalid argument
When I do the 'cp' a typical vmstat shows:
r b swpd free buff cache si so bi bo in cs us
sy id wa
0 0 244 10208 16156 222516 0 0 0 24 1208 819 0
0 0 100
Testing the speed shows:
hdparm -t /dev/hda
Timing buffered disk reads: 14 MB in 3.14 seconds = 4.46 MB/sec
Which is about 1mb slower than the DVD+RW 4x speed as listed in the
specifications sheet .
So far this has only manafesed when attempting to treat a DVD+RW with a
UDF file system as a removable hard disk. Burning a CD-R (I have not
attempted to burn a DVD+R yet) works fine.
Thanks for all the data!
bill davidsen <email@example.com>
CTO TMR Associates, Inc
Doing interesting things with small computers since 1979