Red Hat ENTERPRISE LINUX 5 DM MULTIPATH Configuration And Administration Manual

Chapter 4. The DM-Multipath Configuration File16Attribute Descriptionnext path, the number of requests to send is determined byrr_min_io times the path's priority, as determined by theprio_callout program. Currently, there are priority callouts onlyfor devices that use the group_by_prio path grouping policy,which means that all the paths in a path group will always have thesame priority.If set to uniform, all path weights are equal. The default value isuniform.failback Specifies path group failback.A value of 0 or immediate specifies that as soon as there is apath group with a higher priority than the current path group thesystem switches to that path group.A numeric value greater than zero specifies deferred failback,expressed in seconds.A value of manual specifies that failback can happen only withoperator intervention.The default value is manual.no_path_retry A numeric value for this attribute specifies the number of timesthe system should attempt to use a failed path before disablingqueueing.A value of fail indicates immediate failure, without queuing.A value of queue indicates that queuing should not stop until thepath is fixed.The default value is (null).flush_on_last_del (RHEL 5.3 and later) If set to yes, the multipathd daemon willdisable queueing when the last path to a device has been deleted.The default value is no.queue_without_daemon (RHEL 5.3 and later) If set to no, the multipathd daemon willdisable queueing for all devices when it is shut down. The defaultvalue is yes.user_friendly_names If set to yes, specifies that the system should using the bindingsfile to assign a persistent and unique alias to the multipath, inthe form of mpathn. The default location of the bindings file is/var/lib/multipath/bindings, but this can be changedwith the bindings_file option. If set to no, specifies that thesystem should use use the WWID as the alias for the multipath. Ineither case, what is specified here will be overriden by any device-specific aliases you specify in the multipaths section of theconfiguration file. The default value is no.bindings_file (RHEL 5.2 and later) The location of the bindings file that isused with the user_friend_names option. The default value is /var/lib/multipath/bindings.mode (RHEL 5.3 and later) The mode to use for the multipath devicenodes, in octal. The default value is determined by the process.uid (RHEL 5.3 and later) The user ID to use for the multipath devicenodes. You must use the numeric user ID. The default value isdetermined by the process.