NAME

       multipathd - multipath daemon

SYNOPSIS

       multipathd [options]

DESCRIPTION

       The  multipathd  daemon is in charge of checking for failed paths. When this happens, it will reconfigure
       the multipath map the path belongs to, so that this map regains its maximum performance and redundancy.

       This daemon executes the external multipath config tool when events occur.  In turn, the  multipath  tool
       signals  the  multipathd  daemon  when it is done with devmap reconfiguration, so that it can refresh its
       failed path list.

OPTIONS

       -d     Forground Mode. Don't daemonize, and print all messages to stdout and stderr.

       -v level
              Verbosity level. Print additional information while running multipathd. A  level of 0  means  only
              print errors. A level of 3 or greater prints debugging information as well.

       -B     Read-only  bindings file. Multipathd will not write to the user_friendly_names bindings file. If a
              user_friendly_name doesn't already exist for a device, it will use its WWID as its alias.

       -k     multipathd will enter interactive mode. From this mode, the available commands can  be  viewed  by
              entering "help". When you are finished entering commands, press CTRL-D to quit.

COMMANDS

       The following commands can be used in interactive mode:

       list|show paths
              Show the paths that multipathd is monitoring, and their state.

       list|show maps|multipaths
              Show the multipath devices that the multipathd is monitoring.

       list|show maps|multipaths status
              Show the status of all multipath devices that the multipathd is monitoring.

       list|show maps|multipaths stats
              Show some statistics of all multipath devices that the multipathd is monitoring.

       list|show maps|multipaths topology
              Show the current multipath topology. Same as "multipath -ll".

       list|show topology
              Show the current multipath topology. Same as "multipath -ll".

       list|show map|multipath $map topology
              Show     topology     of    a    single    multipath    device    specified    by    $map,    e.g.
              36005076303ffc56200000000000010aa.  This map could be obtained from "list maps".

       list|show config
              Show the currently used configuration, derived from default values and values specified within the
              configuration file /etc/multipath.conf.

       list|show blacklist
              Show the currently used blacklist rules, derived from default values and values  specified  within
              the configuration file /etc/multipath.conf.

       list|show devices
              Show all available block devices by name including the information if they are blacklisted or not.

       list|show status
              Show  the  number  of  path  checkers  in  each possible state, the number of monitored paths, and
              whether multipathd is currently handling a uevent.

       add path $path
              Add a path to the list of monitored paths. $path is as listed in /sys/block (e.g. sda).

       remove|del path $path
              Stop monitoring a path. $path is as listed in /sys/block (e.g. sda).

       add map $map
              Add a multipath device to the list of monitored devices. $map can either be a device-mapper device
              as listed in /sys/block (e.g. dm-0) or it can be the alias for the multipath device (e.g.  mpath1)
              or the uid of the multipath device (e.g. 36005076303ffc56200000000000010aa).

       remove|del map $map
              Stop monitoring a multipath device.

       resize map|multipath $map
              Resizes map $map to the given size

       switch|switchgroup map $map group $group
              Force  a  multipath  device  to  switch  to a specific path group. $group is the path group index,
              starting with 1.

       reconfigure
              Reconfigures the multipaths. This should be triggered automatically after any hotplug event.

       suspend map|multipath $map
              Sets map $map into suspend state.

       resume map|multipath $map
              Resumes map $map from suspend state.

       fail path $path
              Sets path $path into failed state.

       reinstate path $path
              Resumes path $path from failed state.

       disablequeueing map|multipath $map
              Disabled queuing on multipathed map $map

       restorequeueing map|multipath $map
              Restore queuing on multipahted map $map

SEE ALSO

       multipath(8) kpartx(8) hotplug(8)

AUTHORS

       multipathd was developed by Christophe Varoqui, <christophe.varoqui@opensvc.com> and others.

Linux Administrator's Manual                      November 2009                                    MULTIPATHD(8)