phpman > man > multipathd(8)

MULTIPATHD(8)                          System Manager's Manual                         MULTIPATHD(8)



NAME
       multipathd - Multipath daemon.

SYNOPSIS
       multipathd [-d|-k] [-s] [-v verbosity] [-B] [-w]

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  per‐
       formance and redundancy.

       This  daemon  executes the external multipath 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.

       -n     IGNORED. Use the option find_multipaths to control the treatment of newly detected de‐
              vices by multipathd. See multipath.conf(5).

       -w     Since  kernel  4.14  a  new device-mapper event polling interface is used for updating
              multipath devices on dmevents. Use this flag to force it to use the old event  waiting
              method, based on creating a seperate thread for each device.

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,  for  example
              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  speci‐
              fied within the configuration file /etc/multipath.conf.

       list|show config local
              Show  the currently used configuration like show config, but limiting the devices sec‐
              tion to those devices that are actually present in the system.

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

       list|show devices
              Show  all available block devices by name including the information if they are black‐
              listed 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 mul‐
              tipath  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
              Rereads the configuration, and reloads all changed multipath devices. This  also  hap‐
              pens at startup, when the service is reload, or when a SIGHUP is received.

       reconfigure all
              Rereads  the configuration, and reloads all multipath devices regardless of whether or
              not they have changed. This also happens when multipath -r is run.

       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 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.

       map|multipath $map getprkey
              Get the current persistent reservation key associated with $map.

       map|multipath $map setprkey key $key
              Set the persistent reservation key associated with $map to $key  in  the  prkeys_file.
              This  key  will  only  be  used  by  multipathd  if  reservation_key is set to file in
              /etc/multipath.conf.

       map|multipath $map unsetprkey
              Remove the persistent reservation key associated with $map from the prkeys_file.  This
              will  only  unset  the  key  used  by  multipathd if reservation_key is set to file in
              /etc/multipath.conf.

       path $path setmarginal
              move $path to a marginal pathgroup. The path will remain in the  marginal  path  group
              until  unsetmarginal  is called. This command will only work if marginal_pathgroups is
              enabled and there is no Shaky  paths  detection  method  configured  (see  the  multi‐
              path.conf man page for details).

       path $path unsetmarginal
              return  marginal  path  $path  to its normal pathgroup. This command will only work if
              marginal_pathgroups is enabled and there is no Shaky paths detection method configured
              (see the multipath.conf man page for details).

       map $map unsetmarginal
              return  all  marginal paths in $map to their normal pathgroups. This command will only
              work if marginal_pathgroups is enabled and there is no Shaky  paths  detection  method
              configured (see the multipath.conf man page for details).

       quit|exit
              End interactive session.

       shutdown
              Stop multipathd.

SYSTEMD INTEGRATION
       When  compiled  with systemd support two systemd service files are installed, multipathd.ser‐
       vice 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 re‐
       quired.  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
       multipath-tools was developed by Christophe Varoqui <christophe.varoqui AT opensvc.com> and oth‐
       ers.



Linux                                        2016-10-27                                MULTIPATHD(8)