Date: Mon, 9 Feb 2004 15:47:29 -0800 (PST) From: Dan Strick <strick@covad.net> To: freebsd-questions@freebsd.org Cc: freebsd-hardware@freebsd.org Subject: short read from CD-RW Message-ID: <200402092347.i19NlTRV000718@mist.nodomain>
next in thread | raw e-mail | index | archive | help
I just wrote an iso image to a virgin CD-RW with the following command:
burncd -f /dev/acd0c -s 24 data 5.2.1-RC-i386-disc1.iso fixate
and the burncd program said:
next writeable LBA 0
writing from file 5.2.1-RC-i386-disc1.iso size 657024 KB
written this track 657024 KB (100%) total 657024 KB
fixating CD, please wait..
which is consistent with the iso image file size = 672792576 bytes =
657024 KB = 328512 2KB records. When I read the data back in from
the CD with this command:
dd if=/dev/acd0c of=xxx bs=2k
the dd program says:
dd: /dev/acd0c: Input/output error
328510+0 records in
328510+0 records out
672788480 bytes transferred in 252.669511 secs (2662721 bytes/sec)
which is consistent with the xxx file size = 672788480 bytes = 328510
2KB records. Note that this is 4KB short of the expected file size.
The acd driver produced this error message on the console:
acd0: READ_BIG - MEDIUM ERROR asc=0x11 ascq=0x05 error=0x00
Recent SCSI standards further explain asc=0x11 ascq=0x05 as meaning
"L-EC UNCORRECTABLE ERROR" and "L-EC" as "Layered Error Correction".
I don't believe for a second that my CD medium just happened to have
a bad sector at the very end of the iso disk image. Could this be a
hardware glitch? Could the error message be incorrect?
Is a driver bug involved?
Notes:
1) I am running FreeBSD 4.9-RELEASE.
2) The CD-writer is a SAMSUNG SM-352B.
3) I get similar errors (not sure of the ascq) when any of my CD drives
(both ATA and SCSI) try to read the first blank sector at the end of
a CD-R (should be a short read or EOF).
Dan Strick
strick@covad.net
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200402092347.i19NlTRV000718>