cdrecord warnings

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> [Kevin@Keatings Disk-1]$ cdrecord -dummy -v speed=2 dev=1,0,0 -audio "5th
> Element - The Diva Dance.wav"
> Cdrecord 1.8 (i686-pc-linux-gnu) Copyright (C) 1995-2000 J\u9c0eg Schilling
> TOC Type: 0 = CD-DA
> cdrecord: Operation not permitted. WARNING: Cannot do mlockall(2).
> cdrecord: WARNING: This causes a high risk for buffer underruns.
> cdrecord: Operation not permitted. WARNING: Cannot set RR-scheduler
> cdrecord: Operation not permitted. WARNING: Cannot set priority using
> nice().
> cdrecord: WARNING: This causes a high risk for buffer underruns.
> cdrecord: Operation not permitted. shmctl failed to lock shared memory
> segment
> [Kevin@Keatings Disk-1]$

I think you need to be root to run cdrecord on most systems.

Stan Seibert

Solved: cdrecord suddenly doesn't allow burning

Date: 08/08/03

> > chmod 4710 /usr/bin/cdrecord.*
> > chmod 755 /usr/bin/cdrecord
>
> Thanks, those two commands solved the problems :-)

Cool.

> I don't know the syntax chmod 4710 /usr/bin/cdrecord.*
> ... well I'll have a look at the man page of chmod to
> see what i means exactly :-)

It's a little terse… permit me to waffle :-)

The number 4710 is an octal number, ie. in base eight; each of its digits can have a value from 0 to 7 (decimal) which corresponds to 000 to 111 (binary) - ie. three bits per octal digit. The whole thing, 4 octal digits, is therefore a 12-bit binary number:

  4 7 1 0 octal
1 0 0 1 1 1 0 0 1 0 0 0 binary

which is easy to convert in your head. It also fits neatly into the 12-bit file attributes value that chmod modifies:

         4 7 1 0 octal
  1 0 0 1 1 1 0 0 1 0 0 0 binary
setuid setgid sticky r w x r w x r w x file attributes
   "special" flags user group other

setuid, user: read/write/execute, group: execute-only, other: no access

-rws--x---

The advantage of this method is that when making major changes to a file's permissions, and/or wanting to make sure that you wipe out any possibly untoward remnants of previous permissions, it saves a lot of typing over the chmod ug plus this wibble minus that dance. After a while, values like 4710, 755, 660 and suchlike become instinctive… having to set rw-rw-rw- is a bit dead and chewed though :-)

> By the way, I tried to be sure cd ripping works ok;
> anyway
> cdda2wav -D /dev/cdrom -B
> doesn't give me any problems :-)

OOI is your cdda2wav setuid root? Mine is; this overcomes the problem Andreas mentioned, but I can't remember whether I set it that way or Debian did…

> Thank you for all your advice,

No prob. I take it you meant to post this to the list, rather than to me only? :-)

Pigeon