Multipath Tools; Before You Begin; Preparing San Devices For Multipathing; Section 5.2, "Before You Begin - Novell LINUX ENTERPRISE SERVER 10 - STORAGE ADMINISTRATION GUIDE FOR EVMS Administration Manual

5.1.6 Multipath Tools

The multipath-tools user-space package takes care of automatic path discovery and grouping.
It automatically tests the path periodically, so that a previously failed path is automatically reinstated
when it becomes healthy again. This minimizes the need for administrator attention in a production
environment.
The tools are described in the following table:
Table 5-2
Tool
multipath
multipathd
devmap-name
kpartx
For a list of files included in this package, see the
www.novell.com/products/linuxpackages/suselinux/multipath-tools.html).
Ensure that the multipath-tools package is installed by entering the following at a terminal console
prompt:
rpm -q multipath-tools

5.2 Before You Begin

5.2.1 Preparing SAN Devices for Multipathing

Before configuring multipath I/O for your SAN devices, prepare the SAN devices, as necessary, by
doing the following:
44 SLES 10 Storage Administration Guide for EVMS
Tools Available in the multipath-tools Package
Section 5.2.1, "Preparing SAN Devices for Multipathing," on page 44
Section 5.2.2, "Partitioning Devices that Have Multiple Paths," on page 45
Section 5.2.3, "Configuring mdadm.conf and lvm.conf to Scan Devices by UUID," on page 45
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.
Description
Scans the system for multipathed devices and
assembles them.
Waits for maps events then executes multipath.
Provides a meaningful device name to udev for
device maps (devmaps).
Maps linear devmaps to partitions on the
multipathed device, which makes it possible to
create multipath monitoring for partitions on the
device.
multipath-tools Package Description (http://