Re: cdrecord and "get performance" scsi errors

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

> growisofs 6.1 will error out with:
> # growisofs -Z /dev/scd1=test.iso
> :-( write failed: Invalid argument

Oops. Indeed 6.1 seems to be buggy with this command.
I can reproduce that failure on my machine.

Funnily this gesture works
  dd if=/dev/zero bs=1M count=1000 | \
  /usr/bin/growisofs_6_1 -Z /dev/scd0=/dev/fd/0

The current version 7.0 is ok with both commands.


> /dev/scd1: "Current Write Speed" is 4.1x1385KBps.
> builtin_dd: 2672*2KB out @ average 1.0x1385KBps
> ...
> /dev/scd1: "Current Write Speed" is 2.5x1385KBps.
> builtin_dd: 2672*2KB out @ average 0.6x1385KBps

It seems to react on speed settings. The low average is
due to the small size of the image and the overhead
of burn preparation and and finalization (which lasts
about a minute).

A larger data source (like above dd pipe) would give
pacifier messages with the payload speed. Like:
   778665984/4700372992 (16.6%) @4.0x, remaining 12:45 RBU 100.0%


Have a nice day :)

Thomas