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     Foreground Mode. Don't daemonize, and print all messages to stdout and stderr.

       -s     Suppress timestamps. Do not prefix logging messages with a timestamp.

       -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 paths format $format
              Show  the  paths  that  multipathd  is  monitoring, using a format string with path
              format wildcards.

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

       list|show maps|multipaths format $format
              Show the status of all multipath devices that the multipathd is monitoring, using a
              format string with multipath format wildcards.

       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 wildcards
              Show the format wildcards used in interactive commands taking $format

       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.

       list|show daemon
              Show the current state of the multipathd daemon

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

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

       switch|switchgroup map|multipath $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.

       reset map|multipath $map
              Reassign existing device-mapper table(s) use use the multipath device,  instead  of
              its path devices.

       reload map|multipath $map
              Reload a multipath device.

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

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

       disablequeueing maps|multipaths
              Disable queueing on all multipath devices.

       restorequeueing maps|multipaths
              Restore queueing on all multipath devices.

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

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

       forcequeueing daemon
              Forces  multipathd  into  queue_without_daemon mode, so that no_path_retry queueing
              will not be disabled when the daemon stops

       restorequeueing daemon
              Restores configured queue_without_daemon mode

       map|multipath $map setprstatus
              Enable persistent reservation management on $map

       map|multipath $map unsetprstatus
              Disable persistent reservation management on $map

       map|multipath $map getprstatus
              Get the current persistent reservation management status of $map

       quit|exit
              End interactive session.

       shutdown
              Stop multipathd.

SYSTEMD INTEGRATION

       When  compiled  with  systemd  support  two   systemd   service   files   are   installed,
       multipathd.service  and  multipathd.socket The multipathd.socket service instructs systemd
       to intercept the CLI command socket, so that any call to the CLI interface  will  start-up
       the  daemon  if  required.   The  multipathd.service  file  carries  the  definitions  for
       controlling the multipath daemon.  The daemon itself uses the  sd_notify(3)  interface  to
       communicate with systemd. The following unit keywords are recognized:

       WatchdogSec=
              Enables  the internal watchdog from systemd. multipath will send a notification via
              sd_notify(3) to systemd to reset the watchdog. If  specified  the  polling_interval
              and max_polling_interval settings will be overridden by the watchdog settings.

              Please note that systemd prior to version 207 has issues which prevent the systemd-
              provided watchdog from working correctly.  So  the  watchdog  is  not  enabled  per
              default, but has to be enabled manually by updating the multipathd.service file.

       OOMScoreAdjust=
              Overrides the internal OOM adjust mechanism

       LimitNOFILE=
              Overrides the max_fds configuration setting.

SEE ALSO

       multipath(8) kpartx(8) sd_notify(3) system.service(5)

AUTHORS

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