Re: Re: Recursive copy to udf-formatted dvd-ram freezes system

Johannes Wiedersich wrote:

Eckhard Kosin wrote:

Johannes Wiedersich wrote:

Eckhard Kosin wrote:

But if I try to recursively copy directories to the
udf-formatted

dvd-ram:
cp -r /some/dir /media/cdrecord
than after a few seconds the system
freezes totally - only a power
off/on to reboot is possible.


Also check the output of syslog.


The system freezes a few seconds after starting the copying and after
reboot there is no specific entry in syslog.



Maybe you could also try cp -rv to see if any files get copied.

Are your filenames in accordance to UDF's specifications? I'm not sure
about UDF, but for CDs not any filename that is allowed for ext2 is
also allowed on the CD.

Does this have anything to do with you switching on and off the DVD
drive? Unlike hard disks, cd/dvd writers have a large buffer. My
dvd-ram continues to 'copy' for minutes after the console is finished
with it, ie. it writes the data to buffer and then writes the buffer
to disk. If I switch off the device during that, it hasn't finished
writing and then (of course) damages the UDF filesystem as well.

I would try to reproduce the behaviour with a brand new DVD-Ram disk
and without tempering with the on/off button.


The switching off/on of the writer was only to ensure that the buffer is
empty prior to applying diff and really comparing the files on DVD and
not the buffer to the original files. Of course I waited until the
writing light was off.

The cp -rv showed up a file name with an unprintable character (the file
originated from DOS, long time ago). Thanks. I renamed the file and
now the system doesn't freeze, but the writer doesn't stop to write
(more than 15 min for 293 MB ;-(. No hint from syslog, the only method
to stop the writer is to switch it off and after a new switch on no data
have been written to the DVD. It seems that UDF is rather unstable, at
least in the AMD64 branch.

Thanks for your help

Eckhard
--
Eckhard Kosin
Kaspar-Kerll-Str. 41
D-81245 München, Germany
Tel.: (+49)(+89) 88 88 479
Tel., Fax: (+49)(+89) 835 844
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