Novell LINUX ENTERPRISE SERVER 10 SP2 - STORAGE ADMINISTRATION GUIDE 05-15-2009 Administration Manual page 57

Configuring User-Friendly Names or Alias Names in /etc/multipath.conf
A multipath device can be identified by either its WWID or an alias that you assign for it. The
WWID (World Wide Identifier) is an identifier for the multipath device that is guaranteed to be
globally unique and unchanging. The default name used in multipathing is the ID of the logical unit
as found in the
/dev/disk/by-id
and can change on reboot, referring to multipath devices by their ID is preferred.
/dev/dm-n
The multipath device names in the
always consistent because they use the
association. These device names are user-friendly names such as
You can specify your own device names to use via the ALIAS directive in the
file. Alias names override the use of ID and
multipath.conf
IMPORTANT: We recommend that you do not use aliases for the root device, because the ability to
seamlessly switch off multipathing via the kernel command line is lost because the device name
differs.
For an example of
multipath.conf
tools/multipath.conf.synthetic
1 In a terminal console, log in as the
2 Open the
/etc/multipath.conf
3 Uncomment the
Defaults
4 Uncomment the
user_friendly_names option
For example:
## Use user friendly names, instead of using WWIDs as names.
defaults {
user_friendly_names yes
}
5 Optionally specify your own user-friendly names for devices using the
section.
multipath
For example:
multipath {
wwid 26353900f02796769
alias sdd4l0
}
6 Save your changes, then close the file.
Blacklisting Non-Multipathed Devices in /etc/multipath.conf
The
/etc/multipath.conf
devices should be listed. For example, local IDE hard drives and floppy drives are not normally
multipathed. If you have single-path devices that multipath is trying to manage and you want
to ignore them, put them in the
multipath
For example, to blacklist local devices and all arrays from the
multipath, the
blacklist
directory. Because device node names in the form of
directory reference the ID of the LUN and are
/dev/mapper
/var/lib/multipath/bindings
settings, see the
file.
user.
root
file in a text editor.
directive and its ending bracket.
file should contain a
blacklist
blacklist
section looks like this:
file to track the
.
mpath0
/etc/
/dev/mapper/mpathN
/usr/share/doc/packages/multipath-
, then change its value from No to Yes.
alias
section where all non-multipathed
section to resolve the problem.
driver from being managed by
cciss
Managing Multipath I/O for Devices
/dev/sdn
names.
directive in the
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