Re: Help with DVD+RW w/UDF file system

[Bill Davidsen <davidsen@tmr.com>]

Chris Oxenreider wrote:

> 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
>
> /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
>
> /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 [1].
>
> 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.
>
> [1] 
> http://www.samsung.com/Products/OpticalDiskDrive/DVDRRW/OpticalDiskDrive_DVDRRW_TS_H552U_sp.htm 
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.

Thanks for all the data!

--
bill davidsen <davidsen@tmr.com>
 CTO TMR Associates, Inc
 Doing interesting things with small computers since 1979