Configure Multipath IO Linux

·         Retrieve WWWN for Requesting Storage

systool -c fc_host -v | grep port

    port_id             = "0x021c00"

    port_name           = "0x50014380056631f0"

    port_state          = "Online"

    port_type           = "NPort (fabric via point-to-point)"

    supported_classes   = "Class 3"

    supported_speeds    = "1 Gbit, 2 Gbit, 4 Gbit, 8 Gbit"

    port_id             = "0x021c00"

    port_name           = "0x50014380056631f2"

    port_state          = "Online"

    port_type           = "NPort (fabric via point-to-point)"

    supported_classes   = "Class 3"

supported_speeds    = "1 Gbit, 2 Gbit, 4 Gbit, 8 Gbit"

Record the port_name, you need it to request for the SAN storage.

·     Discouver New LUNs

echo - - - >/sys/class/scsi_host/host0/scan

·         Retrieve the wwid of the LUNs

multipath -l

CluData (360a98000486e5435653457423949616e) dm-4 NETAPP,LUN

[size=50G][features=1 queue_if_no_path][hwhandler=0][rw]

\_ round-robin 0 [prio=0][active]

 \_ 4:0:1:0 sdb 8:16  [active][undef]

 \_ 5:0:1:0 sdd 8:48  [active][undef]

\_ round-robin 0 [prio=0][enabled]

 \_ 4:0:0:0 sda 8:0   [active][undef]

 \_ 5:0:0:0 sdc 8:32  [active][undef]

·         Configure Multipathd for SAN LUN

Save following content as /etc/multipath.conf

Change the wwid and alias to match the LUN you requested.

defaults {

        user_friendly_names yes

}

blacklist {

        devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"

        devnode "^hd[a-z]"

        devnode "^ccis*"

}

multipaths {

        multipath {

                wwid                    360a98000486e5435653457423949616e

                alias                   CluData

        }

}

·         Enable multipathd service

chkconfig multipathd on

service multipathd start

Refer to below post to finish the rest.
http://feijiangnan.blogspot.com/2011/05/how-to-create-linux-lvm.html