HP 3PAR RedHat and Oracle Linux Implementation Guide

Modifying the /etc/modprobe.conf file and Building the Ramdisk
NOTE: The /etc/modprobe.conf file has been deprecated in RHEL 6. In order to make
changes to the ramdisk, create the /etc/modprobe.d/modprobe.conf file.
1. If the HP 3PAR array is running HP 3PAR OS 3.1.1 or later, modify the options qla2xxx
line to include qlport_down_retry=10, as shown below.
The modified output of /etc/modprobe.conf should include the following when the 3PAR
array is running HP 3PAR OS 3.1.1 or later:
NOTE: If the HP 3PAR array is running an HP 3PAR OS version earlier than OS 3.1.1, set
the qlport_down_retry setting to 1 rather than 10.
# cat /etc/modprobe.conf
alias scsi_hostadapter1 qla2xxx
options scsi_mod max_luns=256
options qla2xxx ql2xmaxqdepth=16 qlport_down_retry=10 ql2xloginretrycount=30
If a fan-out configuration is used, where an HP 3PAR StoreServ Storage port is connected to
many hosts through the fabric, it is possible that the target port will run out of I/O buffers and
will result in the target port issuing a QUEUE FULL SCSI status message to any new incoming
I/O requests from any host on that port. To prevent this event, you can throttle the host Port
Queue depth and LUN Queue depth. By default, the QLogic driver sets Port Queue depth
(Execution Throttle) to FFFF (65535) (overriding the default BIOS execution value of 32) and
sets the LUN Queue Depth to 32(default). You can throttle the LUN Queue depth value
to a lower value using the ql2xmaxqdepth parameter. QLogic does not offer any driver setting
to change the Port Queue depth or Execution Throttle. Change the default values if any throttling
is required.
In the following example, the output shows the /etc/modprobe.conf when the
ql2xmaxqdepth is set to 16 for an RHEL server that is connected to an HP 3PAR array that
is running HP 3PAR OS 3.1.1 or later.
# cat /etc/modprobe.conf
alias scsi_hostadapter1 qla2xxx
alias scsi_hostadapter2 qla2300
alias scsi_hostadapter3 qla2322
alias scsi_hostadapter4 qla2400
alias scsi_hostadapter5 qla6312
options scsi_mod max_luns=256
options qla2xxx qlport_down_retry=10 ql2xloginretrycount=30 ql2xmaxqdepth=16
ConfigRequired=0
install qla2xxx /sbin/modprobe --ignore-install qla2xxx
remove qla2xxx /sbin/modprobe -r --first-time --ignore-remove qla2xxx
Required
Storage administrators should carefully consider the number of hosts connected to an HP 3PAR
StoreServ Storage port and the number of LUN exports for calculating the throttling configuration
values. Performance degradation and SCSI timeout issues will result if the values are set too
low.
2. Rebuild the ramdisk image after the /etc/modprobe.conf file entries are modified.
3. To make the changes, you can issue the mkinitrd command or use the QLogic driver script.
# mkinitrd -f -v /boot/initrd-<uname -r>.img <uname -r>
Installing the QLogic HBA 39