link in handbook appears to be broken

Ted Mittelstaedt tedm at
Mon Jun 6 05:16:34 GMT 2005

>-----Original Message-----
>From: owner-freebsd-questions at
>[mailto:owner-freebsd-questions at]On Behalf Of Steven
>Sent: Sunday, June 05, 2005 7:24 PM
>To: Ted Mittelstaedt
>Cc: freebsd-questions at
>Subject: Re: link in handbook appears to be broken
>On Sunday 05 June 2005 06:48 pm, Ted Mittelstaedt wrote:
>> >-----Original Message-----
>> >From: owner-freebsd-questions at
>> >[mailto:owner-freebsd-questions at]On Behalf Of Steven
>> >Friedrich
>> >Sent: Sunday, June 05, 2005 8:20 AM
>> >To: Ted Mittelstaedt
>> >Cc: freebsd-questions at
>> >Subject: Re: link in handbook appears to be broken
>> >
>> >On Saturday 04 June 2005 01:04 am, Ted Mittelstaedt wrote:
>> >> Hi Steven
>> >>
>> >>   Please don't waste time with this.  development of
>burncd is pretty
>> >> much
>> >> dead.  Even the CD's on the list that it supported (of which
>> >
>> >I have one)
>> >
>> >> often didn't work right.  And all of them are old, no longer in
>> >> production.
>> >> burncd is there so if you have a burner sitting around you can plug
>> >> it in and see if it works.
>> >>
>> >>   These days most people use the ATAPI/CAM driver with IDE
>> >
>> >burners, see:
>> >
>> >
>> >
>> >
>> >
>> >> ml#ATAPICAM
>> >>
>> >> Ted
>> >
>> >Ok, but I'm getting nearly the same error with cdrecord.
>> >
>> >cdrecord -blank=all -eject dev=toshiba seemed to work ok.
>> >cdrecord dev=toshiba cd1.iso didn't complain
>> >but then mount /cdrom produced
>> >acd0: READ_BIG - MEDIUM ERROR asc=0x15 ascq=0x00 error=0x00
>> >
>> >
>> >Can someone tell me where to find the meanings of these codes?
>> What you see is what you get - the error "MEDIUM ERROR" seems pretty
>> clear to me - it means that the CD you burned isn't readable.  What
>> are you after - a masters thesis spewed out for every little error?
>> That would bloat the code.
>> FreeBSD tells you there's an error it's your job to find out why
>> there is one.
>> Since as you said in your other posting you are making good CD's at
>> low-speed burn, and frizbees at high speed burn, there is a
>good chance
>> you
>> are underrunning the buffer in the burner.  Get a faster CPU
>or live with
>> lower speed burns.
>> UNIX is a preemptive operating system.  That means that during your CD
>> burn, if something else goes on in the system by some other process,
>> then your burning process gets paused.  If the burner you are
>using has
>> a very small internal buffer than it will run out of data and you will
>> produce a frisbee.
>> WinXP by contrast lets apps like Roxio basically halt the OS while
>> your doing some time-critical operation.  That's fine for a
>> OS but pretty stupid for a server what has lots of people using it
>> all the time.  That is why people don't use WinXP for servers.
>> You cna try playing with the nice command and your cd burns and see if
>> you can make any difference.
>> Ted
>My machines (2) are 2.4 GHz pentium 4s.

OK, in that case chances it's a buffer underrun are much lower.

>I use the same drive
>and media under
>winXP and using Roxio, I've burned freeBSD 4.11 ISOs and booted
>from them.
>The Memorex 1x-4x media worked with cdrecord but the Memorex
>4x-12x media
>doesn't, even when I tell it to burn at 4x like the 1x-4x media did.
>I'm not expecting the software to decode the asc, ascq, and
>error codes, but I
>do expect to find them documented in a header or a book, man
>page, somewhere.

They are documented, these guys have the docs:

You will have to pay them for them.   Or, go to the technical library of
your nearest university and make copies of the appropriate pages of the

ASC = Associated Sense Code
ASCQ = Associated Sense Code Qualifier

These are codes returned to the driver by the CD reader, unexpectedly of
which is why it errored.  The software driver decoded enough to know that
cd reader is reporting a medium error, so it tells you that, then passes
sense code that the reader is returning.  You could look up the sense
in the documentation provided by the manufacturer of the cdrom reader
if you really want to know, and I can almost guarentee you will get

Even if the FreeBSD driver decoded the ASC code, since the ASC code
the drive is returning is garbage, it is useless for you.  Your
getting caught up in minutae during the troubleshooting process rather
focusing on the basics.

The basics are that your burner is producing frisbees.  Now, you know
that the
burner hardware is good under Windows, so that rules out mechanical
You are running a multi-gigahertz CPU so that greatly reduces the
it is buffer underrun issues.  (but not rules them out)
So instead it is likely a software problem.  What you don't know is if
the software
bug that is causing this is in the firmware of the CD reader, the
firmware of
the CD burner, or the FreeBSD device drivers.  The fact it works under
doesen't help because the Windows driver might have been written by
who was aware of whatever firmware bug was present in your burner, and
around that.

So the next step is trying to substitute a different vendor's burner in
the FreeBSD
system.  If it gives you the same errors, the problem is most likely not
in the
burner, and most likely in the software drivers.  With that done, you
have enough data to write a GOOD pr and submit it.  If the substitute
OK then you know it's firmware bugs in the burner you have, and a PR
would not
be warranted.


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