Installation guide

devnode_blacklist {
devnode "^sd[a-z]"
}
You can use a devnode entry in the blacklist section of the configuration file to specify individual
devices to blacklist rather than all devices of specific type; this is not recommended, however. Unless it
is statically mapped by udev rules, there is no guarantee that a specific device will have the same name
on reboot. For example, a device name could change from /dev/sda to /dev/sdb on reboot.
By default, the following devnode entries are compiled in the default blacklist; the devices that these
entries blacklist do not generally support DM-Multipath.
blacklist {
devnode "^(ram|raw|loop|fd|m d|dm-|sr|scd|st)[0-9]*"
devnode "^hd[a-z]"
devnode "^cciss!c[0-9]d[0-9]*"
}
4.3. Configuration File Defaults
The /etc/multipath.conf configuration file includes a defaults section that sets the
user_friendly_nam es parameter to yes, as follows.
defaults {
user_friendly_names yes
}
This overwrites the default value of the user_friendly_nam es parameter.
The configuration file includes a template of configuration defaults. T his section is commented out, as
follows.
#defaults {
# udev_dir /dev
# polling_interval 10
# selector "round-robin 0"
# path_grouping_policy m ultibus
# getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
# prio_callout /bin/true
# path_checker readsector0
# rr_min_io 100
# rr_weight priorities
# failback immediate
# no_path_retry fail
# user_friendly_name yes
#}
To overwrite the default value for any of the configuration parameters, you can copy the relevant line
from this template into the defaults section and uncomment it. For example, to overwrite the
path_grouping_policy parameter so that it is m ultibus rather than the default value of
failover, copy the appropriate line from the template to the initial defaults section of the
configuration file, and uncomment it, as follows.
Red Hat Enterprise Linux 4 DM Multipath
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