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  3. device-mapper-multipath
  4. multipathd(8)

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

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

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

Show the paths that multipathd is monitoring, and their state.
Show the paths that multipathd is monitoring, using a format string with path format wildcards.
Show the multipath devices that the multipathd is monitoring.
Show the current state of the multipathd daemon
Show the status of all multipath devices that the multipathd is monitoring, using a format string with multipath format wildcards.
Show the status of all multipath devices that the multipathd is monitoring.
Show some statistics of all multipath devices that multipathd is monitoring.
Show the current multipath topology. Same as "multipath -ll".
Show the multipath devices that multipathd is monitoring, using JSON formatted output.
Show the current multipath topology. Same as "multipath -ll".
Show topology of a single multipath device specified by $map, e.g. 36005076303ffc56200000000000010aa. This map could be obtained from "list maps".
Show a single multipath device specified by $map, using JSON formatted output.
Show the format wildcards used in interactive commands taking $format
Show the currently used configuration, derived from default values and values specified within the configuration file /etc/multipath.conf.
Show the currently used blacklist rules, derived from default values and values specified within the configuration file /etc/multipath.conf.
Show all available block devices by name including the information if they are blacklisted or not.
Show the number of path checkers in each possible state, the number of monitored paths, and whether multipathd is currently handling a uevent.
Reset the stat counters for all multipath devices.
Reset the stat counters for a specific multipath device.
Add a path to the list of monitored paths. $path is as listed in /sys/block (e.g. sda).
Stop monitoring a path. $path is as listed in /sys/block (e.g. sda).
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).
Stop monitoring a multipath device.
Resizes map $map to the given size
Force a multipath device to switch to a specific path group. $group is the path group index, starting with 1.
Reconfigures the multipaths. This should be triggered automatically after any hotplug event.
Sets map $map into suspend state.
Resumes map $map from suspend state.
Reassign existing device-mapper table(s) use use the multipath device, instead of its path devices.
Reload a multipath device.
Sets path $path into failed state.
Resumes path $path from failed state.
Disable queueing on all multipath devices.
Restore queueing on all multipath devices.
Disable queuing on multipathed map $map
Restore queuing on multipathed map $map
Forces multipathd into queue_without_daemon mode, so that no_path_retry queueing will not be disabled when the daemon stops
Restores configured queue_without_daemon mode
Enable persistent reservation management on $map
Disable persistent reservation management on $map
Get the current persistent reservation management status of $map
Get the current persistent reservation key associated with $map.
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.
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.
End interactive session.
Stop multipathd.

SEE ALSO

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

AUTHORS

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

November 2009 Linux Administrator's Manual