HP StorageWorks Device Mapper Multipath Enablement Kit for HP StorageWorks Disk Arrays installation and reference guide (AA-RW8RE-TE, June 2009)

4 Using DM Multipath
This chapter addresses the following topics:
• Creating an alias using /etc/multipath.conf file
• Clustering Solutions with DM Multipath
Creating an alias using /etc/multipath.conf file
This section describes various parameters available for updating /etc/multipath.conf file.
The multipath devices are created in the /dev/mapper directory in the hosts. These devices are
similar to any other block devices present in the host, and are used for any block or file level I/O
operations, such as creating the file system.
You must use the devices under /dev/mapper/. You can create a new device alias by using the
alias and the WWID attributes of the multipath device present in the multipath subsection of the/
etc/mutipath.conf file.
Example 1. Updating /etc/multipath.conf file
For example, when the following subsection is added in the /etc/multipath.conf file for the
LUN with WWID 3600508b30090f5d0d2a9d64590490022, a multipath device, mydatadisk1,
is created under /dev/mapper:
multipaths
{
multipath
{
123456789987654321
mydatadisk1
multibus
tur
"round-robin 0"
wwid
alias
path_grouping_policy
path_checker
path_selector
}
}
You can use /dev/mapper/mydatadisk1 like any other block device.
Using Multipath map
This section describes a multipath map obtained by executing the multipath–ll command, based on
a sample multipath.conf file.
Device Mapper Multipath Enablement Kit for HP StorageWorks Disk Arrays installation and reference
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