Red Hat Bugzilla – Bug 124965
System hangs with cdrecord, SG_IO and scsi cdwriter
Last modified: 2015-01-04 17:06:43 EST
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Description of problem:
cdrecord hangs system at the stage
"Blanking PMA, TOC, pregap"
and again at the stage
At these stages the whole system hangs for about 30 seconds, then
resumes normal operation. I have a scsi cdwriter and I am using
cdrecord -v speed=4 dev=/dev/cdrom1 blank=fast filename.iso
to execute cdrecord. On previous versions before the introduction of
SG_IO I never had this problem.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. cdrecord -v speed=4 dev=/dev/cdrom1 blank=fast filename.iso
Actual Results: system hangs, then resumes about 30 seconds later.
Expected Results: no hang.
which scsi controller is this ? which burner ?
can you attach the output of "cat /proc/scsi/scsi" and of dmesg ?
Created attachment 100752 [details]
Created attachment 100753 [details]
Scsi controller is Adaptec 19160 using module aic7xxx.
The burner is a Yamaha CRW2100S
to the cdrecord command line options
I tried it with the -immed option and it has fixed the problem, I got
a slight jump on audio playback at the âfixating...â stage, but no
system hangs, which is good enough for me :-)
I've done a little bit of reading about IMMED and found that it is
used to stop a device using all the bandwidth of the bus it is on. I
would understand why this would fix my problem if my hard disk and my
cd-writer were on the same bus but they are on 2 separate buses, with
2 separate cables. My hard disk is on the U160 bus, with its own 68pin
cable. And My cd-writer is on another bus (don't know which scsi
version it is, but it's on its own 50pin cable).
Do you have any idea's why this fixes my problem ?
Also do you know why this problem has only arisen since the
introduction of SG_IO ?
This problem has been totally fixed since I upgraded to FC3
(kernel-2.6.9-1.681_FC3), I'm not even getting the slight jump on
audio playback anymore.