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.