Red Hat DEVICE-MAPPER MULTIPATH 5.2 Configuration And Administration Manual page 31

# udev_dir
# polling_interval
# selector
# path_grouping_policy
# getuid_callout
# prio_callout
# path_checker
# rr_min_io
# rr_weight
# failback
# no_path_retry
# user_friendly_name
#}
To overwrite the default value for any of the configuration parameters, you can copy the
relevant line from this template into the
overwrite the
path_grouping_policy
value of , copy the appropriate line from the template to the initial
failover
the configuration file, and uncomment it, as follows.
defaults {
user_friendly_names
path_grouping_policy
}
Table 4.1, "Multipath Configuration Defaults"
section of the
defaults
DM-Multipath unless they are overwritten by the attributes specified in the
sections of the
multipaths
Attribute
udev_dir
polling_interval
selector
path_grouping_policy
/dev
10
"round-robin 0"
multibus
"/sbin/scsi_id -g -u -s /block/%n"
/bin/true
readsector0
100
priorities
immediate
fail
yes
defaults
parameter so that it is
yes
multibus
describes the attributes that are set in the
configuration file. These values are used by
multipath.conf
file.
multipath.conf
Description
Specifies the directory where
The default value is
Specifies the interval between two path checks in seconds.
The default value is 5.
Specifies the default algorithm to use in determining what
path to use for the next I/O operation. The default value is
round-robin 0
Specifies the default path grouping policy to apply to
unspecified multipaths. Possible values include:
= 1 path per priority group
failover
= all valid paths in 1 priority group
multibus
group_by_serial
number
group_by_prio
Configuration File Defaults
section and uncomment it. For example, to
multibus
device nodes are created.
udev
.
/udev
.
= 1 priority group per detected serial
= 1 priority group per path priority value
rather than the default
section of
defaults
and
devices
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