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

[Eckhard Kosin <Eckhard.Kosin@online.de>]

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
  mailto:Eckhard.Kosin@online.de