[Debburn-devel] Buffer underrrun warning in wodim

[Sebastian Kemper]

On Sat, Mar 08, 2008 at 04:00:17PM +0100, oscar megia wrote:
> /usr/bin/wodim: Operation not permitted. WARNING: Cannot set RR-scheduler
> /usr/bin/wodim: Permission denied. WARNING: Cannot set priority using
> setpriority().
> /usr/bin/wodim: WARNING: This causes a high risk for buffer underruns.
> Error: Cannot gain SYS_RAWIO capability, is wodim installed SUID root?
> Reason: Operation not permitted

Hi!

Set wodim SUID root. That way it can raise its priority. Say you distro
uses the group 'cdrom' to distinguish between allowed-to-burn and
not-allowed-to-burn users (check device permissions of burner):

cd /usr/bin
chown root:cdrom wodim
chmod 4710 wodim

Now wodim is set SUID root.

Another thing worth checking is that your drive has DMA enabled (hdparm
/dev/hdX).

> /usr/bin/mkisofs: Input/output error. Cannot read from '/mnt/Joaquin
> sabina -19 dias y 500 noches/08-Donde_habita_el_olvido.mp3'

Is the file readable by your user? Check permissions. Also check your
syslog if it happens again. Maybe your disk has bad sectors. Or maybe
the mp3 itself is broken.

Burning CD-Rs at 24x is also helpful. Lowers the chance of buffer
underuns and occasionally it can improves burning quality.

Hope this helps
Sebastian