HP 3PAR RedHat and Oracle Linux Implementation Guide

3. To control how often a ping is sent by the iSCSI initiator to the iSCSI target, change the
following parameter.
node.conn[0].timeo.noop_out_interval = [replacement_timeout]
To detect problems quickly in the network, the iSCSI layer sends iSCSI pings to the target. If
the ping times out, the iSCSI layer responds by failing running commands on the path where
the pings failed.
4. Set this parameter to 10 seconds.
node.conn[0].timeo.noop_out_interval = 10
5. To set the host log into the iSCSI nodes every time the iSCSI daemon is started or the host is
rebooted, edit the iSCSI configuration in /etc/iscsi/iscsid.conf and change the values
of the following default settings:
node.startup = automatic
node.conn[0].startup = automatic
NOTE: The node.conn[0] .startup variable is optional and not defined in the default
iscsid configuration file.
6. Check the state of the iSCSI service run level with the chkconfig command:
# chkconfig --list | grep iscsi
iscsi 0:off 1:off 2:off 3:off 4:off 5:off 6:off
iscsid 0:off 1:off 2:off 3:on 4:on 5:on 6:off
7. Verify that Run level 5 is turned on. If not turned on, issue the following commands:
# chkconfig iscsi on
# chkconfig --list|grep iscsi
iscsi 0:off 1:off 2:on 3:on 4:on 5:on 6:off
iscsid 0:off 1:off 2:off 3:on 4:on 5:on 6:off
8. Session and device queue depth in /etc/iscsi/iscsid.conf may require tuning
depending on your particular configuration. node.session.cmds_max controls how many
commands the session will queue. node.session.queue_depth controls the device's
queue depth.
If you are deploying HP 3PAR Priority Optimization software, you may need to increase or
max out the node.session.cmds_max and node.session.queue_depth values to
ensure the host has sufficient I/O throughput to support this feature. For complete details of
how to use HP 3PAR Priority Optimization (Quality of Service) on HP 3PAR StoreServ Storage
arrays, see the HP 3PAR Priority Optimization technical white paper, available on the following
website:
HP 3PAR Priority Optimization
In a multihost-to-single HP 3PAR StoreServ Storage configuration when HP 3PAR Priority
Optimization is not in use it is possible to overrun the array target port I/O queues or
experience queue starvation for some hosts due to excessive usage by other hosts. This situation
is more likely when using the 1G iSCSI target ports on T-Class and F-Class HP 3PAR StoreServ
Configuring RHEL 6 or RHEL 5 for Software and Hardware iSCSI 59