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Enabling Multipath I/O functionality on SLES 11 involves the iSCSI initiator, the

multipath subsystem and device mapper. This configuration procedure details the

steps required to utilize multiple Ethernet interface connections between a SLES 11 SP1

server and a PS Series storage array.

Before beginning the multipath I/O configuration, it is recommended that existing

iSCSI volumes be unmounted and the iscsiadm record database be empty. Be sure to

complete the steps listed in “Task #4 – Delete the Volumes”, above.

1) Verify there are no active sessions in the iSCSI record database:

# iscsiadm --mode session

iscsiadm: No active sessions.

Note: If there are volumes listed, use the ‘iscsiadm –o delete’ command to

manually delete the records. Use ‘iscsiadm –-logoutall=all’ to logout of all targets

before manually deleting the records. Be sure to enter the appropriate iscsi

targetname (-T <iqn>).

2) Create the interface files for the two Ethernet paths:

# iscsiadm --mode iface --interface eth2 -o new

New interface eth2 added

# iscsiadm --mode iface --interface eth3 -o new

New interface eth3 added

3) Add an interface name for the two Ethernet ports. In the test configuration, the

interface names

are ‘eth2 and ‘eth3’:

# iscsiadm --mode iface --interface eth2 -o update --name

iface.net_ifacename -–value=eth2

eth2 updated.

# iscsiadm --mode iface --interface eth3 -o update --name

iface.net_ifacename -–value=eth3

eth3 updated.

These commands have created two iSCSI interface files, the contents of which

should look like these (eth2 and eth3):

# iscsiadm -m iface -I eth2

# BEGIN RECORD 2.0-871

iface.iscsi_ifacename = eth2

iface.net_ifacename = eth2

iface.ipaddress = <empty>

iface.hwaddress = <empty>

iface.transport_name = tcp

iface.initiatorname = <empty>

# END RECORD

# iscsiadm -m iface -I eth3

# BEGIN RECORD 2.0-871

iface.iscsi_ifacename = eth3

iface.net_ifacename = eth3