Configuring The System For Multipathing; Preparing San Devices For Multipathing - Novell LINUX ENTERPRISE SERVER 11 - STORAGE ADMINISTRATION GUIDE 2-23-2010 Administration Manual

multipath -p
[failover|multibus|group_by_serial|group_by_prio|group_by_node_name]
Specify one of the group policy options that are described in
Group Policy Options for the multipath -p Command
Table 7-3
Policy Option
failover
multibus
group_by_serial
group_by_prio
group_by_node_name

7.4 Configuring the System for Multipathing

Section 7.4.1, "Preparing SAN Devices for Multipathing," on page 54
Section 7.4.2, "Partitioning Multipathed Devices," on page 55
Section 7.4.3, "Configuring the Server for Multipathing," on page 55
Section 7.4.4, "Adding multipathd to the Boot Sequence," on page 56
Section 7.4.5, "Creating and Configuring the /etc/multipath.conf File," on page 56

7.4.1 Preparing SAN Devices for Multipathing

Before configuring multipath I/O for your SAN devices, prepare the SAN devices, as necessary, by
doing the following:
Configure and zone the SAN with the vendor's tools.
Configure permissions for host LUNs on the storage arrays with the vendor's tools.
Install the Linux HBA driver module. Upon module installation, the driver automatically scans
the HBA to discover any SAN devices that have permissions for the host. It presents them to
the host for further configuration.
NOTE: Ensure that the HBA driver you are using does not have native multipathing enabled.
See the vendor's specific instructions for more details.
After the driver module is loaded, discover the device nodes assigned to specific array LUNs or
partitions.
54 SLES 11: Storage Administration Guide
Description
One path per priority group. You can use only one path at a time.
All paths in one priority group.
One priority group per detected SCSI serial number (the controller node
worldwide number).
One priority group per path priority value. Paths with the same priority are in the
same priority group. Priorities are determined by callout programs specified as
a global, per-controller, or per-multipath option in the
configuration file.
One priority group per target node name. Target node names are fetched in the
/sys/class/fc_transport/target*/node_name
Table 7-3:
/etc/multipath.conf
location.