Red Hat Bugzilla – Bug 124965
System hangs with cdrecord, SG_IO and scsi cdwriter
Last modified: 2015-01-04 17:06:43 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510 Description of problem: cdrecord hangs system at the stage "Blanking PMA, TOC, pregap" and again at the stage "Fixating..." 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): kernel-2.6.5-1.358 How reproducible: Always 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. Additional info:
which scsi controller is this ? which burner ?
can you attach the output of "cat /proc/scsi/scsi" and of dmesg ?
Created attachment 100752 [details] dmesg
Created attachment 100753 [details] cat /proc/scsi/scsi
Scsi controller is Adaptec 19160 using module aic7xxx. The burner is a Yamaha CRW2100S
Try adding -immed 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.