Do I need to mkinitrd when changing QLogic queue depth?

Yong Huang yong321 at
Tue Jan 20 22:29:25 UTC 2009

I'd like to benchmark I/O performance with different QLogic driver queue depth. According to
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
inspires me to do the test.)

Yong Huang


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