data overrun from CD / USB cd mount errors - freebsd 5.2.1 (fwd)

[Streiner, Justin]

Is it possible that the way the CD drive gets mounted, or the type of CD
(burned on a winXP machine) could have an impact on the ability to
reliably read from the disc?  If I just do:

mount /cdrom
cp /cdrom/* /data/

I can reproduce the read/overrun errors pretty reliably.

If I do something like pull lots of distributions from the freebsd cd set
I burned from the ISO images, sysinstall never complains about any problems
and the packages are copied and installed cleanly.

Any ideas on what could be causing this?

jms

---------- Forwarded message ----------
Date: Sat, 27 Mar 2004 16:29:39 -0500 (EST)
From: "Streiner, Justin" <streiner at stargate.net>
To: freebsd-questions at freebsd.org
Subject: data overrun from CD / USB cd mount errors - freebsd 5.2.1

I recently installed freebsd 5.2.1 from CD images that I burned on another
machine.  The CD drive in my new machine worked fine to install the OS and
things are for the most part up and running now.  The issue I'm having now
is in copying more data I have burned on CDs onto the new system.  Sometimes
when I copy a CD, I start getting the following errors:

Mar 22 20:25:33 whammy kernel: acd0: FAILURE - READ_BIG status=51
<READY,DSC,ERROR> sensekey=MEDIUM ERROR error=4<ABORTED>

Mar 23 15:47:27 whammy kernel: acd0: WARNING - READ_BIG read data overrun
4096>2048
Mar 23 15:47:27 whammy kernel: acd0: WARNING - READ_BIG read data overrun
2048>0

The files copies to the hard drive are usually blantantly incomplete or
corrupted (file sizes don't match), and in many cases when the file sizes
do match, an MD5 checksum comparison between the original file on the CD
and the file that was copied to the hard drive does not.

This is a pretty normal ATAPI CDROM.  dmesg reports:
acd0: CDROM <SAMSUNG SC-140B> at ata1-master PIO4

Other posts I've read over on similar subjects suggest that perhaps the DMA
mode for this CDROM needs to be tweaked.  Could this be the case here?

I also have an external USB CD burner that appears to be at least partially
supported by my system, as reported by dmesg:
Mar 22 20:09:05 whammy kernel: GEOM: create disk cd0 dp=0xc1cec600
Mar 22 20:09:05 whammy kernel: cd0 at umass-sim0 bus 0 target 0 lun 0
Mar 22 20:09:05 whammy kernel: cd0: <ATAPI CD-R/RW 40X12 3.CB> Removable
CD-ROM SCSI-0 device
Mar 22 20:09:05 whammy kernel: cd0: 1.000MB/s transfers
Mar 22 20:09:05 whammy kernel: cd0: cd present [358497 x 2048 byte records]

When I try to mount this device, I get the following errors:
umass0: Unsupported ATAPI command 0x43

I don't think the block device for /dev/cd0 is set up properly, but I can't
seem to build a new one with mknod.

crw-r-----  1 root  operator    4,  34 Mar 22 20:08 /dev/cd0

Any ideas what may be going on here / how I can fix these issues?

jms
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