Queue depth is something that is normally changed at the HBA driver level. Can you let us know what make/model of HB, driver and O/S and we should be able to point you in the right direction.

cheers

Conor

hi conor,

im using a 64bit windows 2003 with qlogic 2 x 2432 using qlogic driver 9.1.7.16.

thanks again.

This discussion over on the QLogic forums:
http://solutions.qlogic.com/KanisaSupportSite/search.do?cmd=viewThread&docType=tkc&kcId=Post-7926001&sliceId=Post-7926001&dialogID=82092957&stateId=1%200%2082046439

suggests that you can adjust queue-depth using a registry setting HKLM\SYSTEM\CurrentControlSet\Services\Ql2300\Paramters\Device\qd

where qd can be set to up to 254 (default 32).

i was going to mention that QD setting only applies to scsi miniport driver, not the storport driver. like the previous posted hyperlink to qlogic forum mentions . this QD setting will have no effect on later scsi storport driver.

here too in LINUX ..

# cat /etc/modules.conf|grep ql2xmaxqdepth
options qla2300 ql2xmaxqdepth=64

PowerPath cannot help with the Queue Depth.

For the QLogic STORport drivers the Queue Depth parameter is called Max Throttle - it can be changed using the SANSurfer utility. EMC recommended value is 256. However if you have RecoverPoint then EMC recommends lowering this to max 250.

If you have a large number of devices then you can lower this setting depending on the issues you are seeing. Note if you are having no issues with connectivity then I would recommend you leave the setting alone.

Further the Max Throttle setting is a HBA wide Queue Depth. Qlogic do not implement a queue per device as Emulex is capable of.