multipathd man page

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.
-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 daemon
Show the current state of the multipathd daemon
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 multipathd is monitoring.
list|show maps|multipaths topology
Show the current multipath topology. Same as "multipath -ll".
list|show maps|multipaths json
Show the multipath devices that multipathd is monitoring, using JSON formatted output.
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 map|multipath $map json
Show a single multipath device specified by $map, using JSON formatted output.
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.
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 multipathed 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.

See Also

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

Authors

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

Referenced By

blkdeactivate(8), kpartx(8), mpathconf(8), multipath(8), multipath.conf(5).

November 2009 Linux Administrator's Manual