HP 3PAR RedHat and Oracle Linux Implementation Guide

2. Create udev rules 56_3par_timeout.rules under /etc/udev/rules.d with the
following contents:
/etc/udev/rules.d/56-3par.timeout.rules
KERNEL="sd*[!0-9]", SYSFS{vendor}="3PARdata", PROGRAM="/bin/sh -c 'echo 60 >
/sys/block/%k/device/timeout'" NAME="%k"
Required
Make sure there is no break between the two lines in the 56-3par-timeout.rules.
The udev rule number 56-3par-timeout.rules should follow after the 51-by-id.rules.
Change the udev rule number accordingly.
The 56-3par-timeout.rules is selected based on the test system configuration. See
“Using UDEV Rules to Set the SCSI Timeout” (page 45) to verify that the
56-3par-timeout.rulesudev rule is working.
# ls /etc/udev/rules.d/
. . . . .
40-multipath.rules
50-udev.rules
51-by-id.rules
56-3par-timeout.rules
Verifying the SCSI Timeout Settings
Verify the udev rules setting after the HP PAR storage volumes have been exported to the host For
details, see“Allocating Storage for Access by the RHEL Host” (page 103).
# udevinfo -a -p /sys/block/sdx
For example:
# udevinfo -a -p /sys/block/sdn |grep timeout
SYSFS{timeout}="60"
On RHEL 6, you can also verify the SCSI timeout settings as follows:
cat /sys/class/scsi_device/*/device/timeout
On RHEL 5 using Emulex HBAs, verify using the following:
/sys/class/scsi_device/*/device/timeout
If the udev rule is created after the host sees HP 3PAR StoreServ Storage volumes, execute the
udevstart command, which runs the udev rules on all devices and sets the timeout to 60. The
time it takes for the udevstart command to complete is based on the number of devices and
I/O throughput, so the recommendation is to run the command during non-peak activity.
# udevstart
Rebooting the host starts the udev rule by default.
46 Configuring a Host with Fibre Channel