lost SCSI IO

From: NucleoDyne Systems Inc.
Date: Mon Dec 08 2003 - 14:35:11 EST


I have been developing a SCSI based application and facing hardship due to lack of better debugging support in SCSI domain on linux. May be I am not very familiar with linux scsi subsystem.

I have a lost IO, sitting somewhere in some queue. The scsi logging facility has been turned on with : echo "scsi log all" > /proc/scsi/scsi.

The syslog shows that the request has started:
scsi_do_req (host = 0, channel = 0 target = 3, buffer =00000000, bufflen = 0, d)command : 00 20 00 00 00 00
Leaving scsi_do_req()

The SCSI bus trace does not show any activity.

I guess only way to find out the state of the IO is to put printf and recompile the kernel. HP-UX had facilities like lkcd, linux crash dump analyzer. I used to be called q4. A perl script could be written to navigate kernel data structures and extract information from them on a running system. If we had that kind of tool already into linux then debugging the live system would be easier.

Is there a plan to include lkcd into default kernel?



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