Technical data

3Configuring HPDM M ultipath
This chapter addresses the following topics:
• Using /etc/multipath.conf File
• Starting HPDM Multipath
Using /etc/multipath.conf File
The first step of configuring HPDM Multipath involves editing the /etc/multipath.conf con figuration
file, which is distributed as part of the HPDM Multipath tools user space package. This file also enables
you to customize HPDM Multipath for a variety of SAN stor age subsystems .
The multipath.conf file provides the following options to configure the attributes of a multipath
device:
• I/O gr ouping policy
• polling interval for subsequent path status verification
• path select
or algorithm
• program used by multipath to obtain a unique path identifier
The HPDM Multipath package comes with a template file with the recommended configuration for
HP supported arrays. To use this template file:
For RHEL systems:
1. Copy the /u
sr/share/doc/HPDMmultipath-tools-4.0.0/multipath.conf.HPTem-
plate file as /etc/multipath.conf
For SLES systems:
1. Copy the /
usr/share/doc/packages/HPDMmultipath-tools-4.0.0/
multipath.conf.HPTemplate file as /etc/multipath.conf
The /etc/multipath.conf file consists of the following sections, to con fig ure the attributes of a
multipat
hdevice:
• System defaults (defaults)
• Black-listed devices (devnode_blacklist/blacklist)
• Storage
array model settings (devices)
• Multipath device settings (multipaths)
• Blacklist exceptions (blacklist_exceptions)
The defaults section defines default values for attributes which are used whenever required setting
is unavailable. The blacklist section defines which devices should be excluded from the multipath
topolo
gy discovery. The blacklist_exceptions section defines which devices should be included in
the multipath topology discovery, despite being listed in the blacklist section. The multipaths
section defines the multipath topologies. They are indexed by a World Wide Identifier (wwi d). The
devices section defines the device-specific settings based on vendor and product values.
Table 3 lists the important attributes of HP supported arrays.
Device Mapper Multipath Enablement Kit for HP StorageWorks Disk Arrays
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