HP 3PAR RedHat and Oracle Linux Implementation Guide

Connect the RHEL host iSCSI initiator port(s) and the HP 3PAR StoreServ Storage iSCSI target ports
to the switch(es).
If you are using VLANs, make sure that the switch ports which connect to the HP 3PAR StoreServ
Storage iSCSI target ports and iSCSI initiator ports reside in the same VLANs and/or that you can
route the iSCSI traffic between the iSCSI initiator ports and the HP 3PAR StoreServ Storage iSCSI
target ports. Once the iSCSI initiator and HP 3PAR StoreServ Storage iSCSI target ports are
configured and connected to the switch, you can use the ping command on the iSCSI initiator host
to make sure it sees the HP 3PAR StoreServ Storage iSCSI target ports.
NOTE: Setting up the switch for VLAN and routing configuration is beyond the scope of this
document. Consult your switch manufacturer's guide for instructions about setting up VLANs and
routing.
The procedures in this chapter assume that you have completed the following tasks:
• Setup and configuration of the host Network Interface Card (NIC) or converged network
adapter (CNA) as Initiator port that will be used by the iSCSI Initiator software to connect to
the HP 3PAR StoreServ Storage iSCSI target ports.
• Installation of the iSCSI initiator software package.
Installing iSCSI on RHEL 6 or RHEL 5
iSCSI is installed through the iscsi-initiator-utils driver and rpm package by default
during the RHEL installation. There are a couple of ways to configure and start
iscsi-initiator-utils on RHEL: either by using the various iscsi-initiator-utils
commands available from the RHEL CLI or through the GUI.
This document references the iscsi-initiator-utils commands from the RHEL CLI. The
iscsiadm utility is a command-line tool that allows discovery and login to iSCSI targets. This tool
also provides access and management of the open-iscsi database. The following steps are
required to discover iSCSI sessions:
1. Discover targets at a given IP address.
2. Establish iSCSI login with the node record ID found in the discovery process.
3. Record iSCSI session statistics information.
Setting Up Software iSCSI for RHEL 6 or RHEL 5
You can adjust the iSCSI timers for better iSCSI session management and iSCSI I/O path
management. iSCSI timers and session parameters are specified in /etc/iscsi/iscsid.conf
file.
The replacement_timeout iSCSI timeout parameter prevents I/O errors from propagating to
the application by controlling how long the iSCSI layer should wait for a timed-out path/session
to reestablish itself before failing any commands on it. The default replacement_timeout value
is 120 seconds.
To adjust replacement_timeout, complete the following steps:
1. Open /etc/iscsi/iscsid.conf and edit the following line:
node.session.timeo.replacement_timeout = [replacement_timeout]
2. Set this parameter to 10 seconds for a faster failover.
node.session.timeo.replacement_timeout = 10
58 Configuring a Host with iSCSI