Do I need to mkinitrd when changing QLogic queue depth?
Yong Huang
yong321 at yahoo.com
Tue Jan 20 22:29:25 UTC 2009
I'd like to benchmark I/O performance with different QLogic driver queue depth. According to
http://publib.boulder.ibm.com/infocenter/svcic/v3r1m0/index.jsp?topic=/com.ibm.storage.svc.console.doc/svc_linsetqdepth_1dcv4w.html
I need to mkinitrd after I make the changes in /etc/modprobe.conf. Why? I won't change kernel.
This is for both RH 4 and 5. I think I can check the current queue depth by any of the following:
cat /sys/class/scsi_device/*/device/queue_depth
grep "queue depth" /proc/scsi/qla2xxx/* (only found on RH4)
cat /proc/scsi/sg/device_hdr /proc/scsi/sg/devices (the qdepth column)
It looks like RH4 uses 16 and RH5 32.
(In case you ask why, this article
http://dsstos.blogspot.com/2008/12/hostlun-queue-depths-command-taq.html
inspires me to do the test.)
Yong Huang
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