set scsi_options
2007-12-25 10:31:00
I asked about how to turn off TCQ (Tagged Command Queuing) on a perticular
scsi drive. Many people responded and here is the summary:
+ A line "set scsi_options & ~0x80" in /etc/system file disables TCQ surely.
it is equivalent to "set scsi_optons = 0x378". It switches of TCQ bit and
leaves other bits alone.
+ The above line takes effect on all scsi drives, so it's better just disable
TCQ on the problematic disk drive, the one that has "disconnected tagged cmds
timeout" message. To turn off TCQ for scsi target 4, I created the file
/kernel/drv/esp.conf with the following contents:
name="esp" parent="/iommu@f,e0000000/sbus@f,e0001000/espdma@f,400000"
reg=0xf,0x800000,40
target0-scsi-options=0x378;
I then shutdown and power cycled the machine, rebooted the system with -r.
+ Useful man pages, files etc.: man esp, man -s 4 system,
/usr/include/sys/scsi/conf/autoconf.h file, and Cockcrof's book
The disk has been run happily since I reconfigured the system, and hope it
runs happily ever after :)
My sincere thanks to you, my fellow managers:
Michael Neef neef@neuroinformatik.ruhr-uni-bochum.de
Nate Itkin Nate-Itkin@ptdcs2.intel.com
Thai Dang dangthai@emc.com
Casper Dik casper@holland.Sun.COM
John Benjamins johnb@freenet.hamilton.on.ca
Simon Gibbons simong@aifs.org.au
Fedor Gnuchev qwe@ht.eimb.rssi.ru
Dan Razell razzell@cs.ubc.ca
Susan Feng
--
-----------------------------------------------------------------------------
Susan Feng (aka. Xueshan Feng) Computer Administration Support Team
Sr. Unix System Administrator Distributed Computing Group
Internet: sfeng@cast.stanford.edu Stanford University
Office Phone: 415 723-1004 Stanford CA 94305
Fax: 415 725-1548
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