HP 3PAR RedHat and Oracle Linux Implementation Guide

Using Emulex Scripts to Set the SCSI Timeout
If the udev rule was not implemented, you can change the SCSI timeout value from 30 seconds
to 60 seconds by running the set_target_timeout.sh. You can download this shell script
from the following website:
Emulex
Selecting Linux Tools on the Emulex Linux driver download website. The timeout value is a dynamic
variable and can be changed even while I/O is being served on the devices.
Example: Emulex changing timeout script:
# ./set_target_timeout.sh <host_num> <target_id> <cmd_timeout>
# ls /sys/class/scsi_host/host2/device
… target2:0:0
The SCSI instance number is 2 and target is 0 from the above output:
# ./set_target_timeout 2 0 60
modifying device /sys/class/scsi_device/2:0:0:0/device
found timeout at value 30
new timeout value is 60
modifying device /sys/class/scsi_device/2:0:0:1/device
found timeout at value 30
new timeout value is 60
. . .
You can also manually change the timeout value using the following commands:
# /sys/class/scsi_device/2:0:0:0/device
# echo 60 > timeout
# cat timeout
60
The set_target_timeout script needs to be executed for all the SCSI instances of lpfc driver;
if the operation if performed manually, the command needs to be executed for all the devices.
NOTE: If the Emulex driver is unloaded and reloaded for any reason, the timeout setting will
reset to the default setting of 30 seconds for all Emulex attached devices. If this occurs, set the
timeout value back to 60 seconds using any of the described methods. This is not applicable if the
timeout is changed using the udev rule.
Setting Up Multipathing Software
HP supports the following multipath solutions for RHEL:
• Device-mapper
• Veritas Dynamic MultiPathing (DMP)
Setting Up Device-mapper
Check for installed Device-mapper packages by issuing rpm -qa|grep device-mapper.
NOTE: If necessary, install the device-mapper-multipath package using the RHEL tools.
48 Configuring a Host with Fibre Channel