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

NAME

multipath - Device mapper target autoconfig.

SYNOPSIS

multipath [-v verbosity] [-b bindings_file] [-d] [-h|-l|-ll|-f|-t|-T|-F|-B|-c|-C|-q|-r|-i|-a|-u|-U|-w|-W] [-p failover|multibus|group_by_serial|group_by_prio|group_by_node_name] [-R retries] [device]

DESCRIPTION

multipath is used to detect and coalesce multiple paths to devices, for fail-over or performance reasons.

OPTIONS

Verbosity, print all paths and multipaths:
0
No output.
1
Print the created or updated multipath names only, for use to feed other tools like kpartx.
2 +
Print all info: detected paths, coalesced paths (ie multipaths) and device maps.
Print usage text.
Dry run, do not create or update devmaps.
Show the current multipath topology from information fetched in sysfs and the device mapper.
Show the current multipath topology from all available information (sysfs, the device mapper, path checkers ...).
Flush a multipath device map specified as parameter, if unused.
Flush all unused multipath device maps.
Display the currently used multipathd configuration.
Display the currently used multipathd configuration, limiting the output to those devices actually present in the system. This can be used a template for creating multipath.conf.
Force devmap reload.
Ignore WWIDs file when processing devices. If find_multipaths strict or find_multipaths no is set in multipath.conf, multipath only considers devices that are listed in the WWIDs file. This option overrides that behavior. For other values of find_multipaths, this option has no effect. See the description of find_multipaths in multipath.conf(5). This option should only be used in rare circumstances.
Treat the bindings file as read only.
Set user_friendly_names bindings file location. The default is /etc/multipath/bindings.
Check if a block device should be a path in a multipath device.
Check if a multipath device has usable paths. This can be used to test whether or not I/O on this device is likely to succeed. The command itself doesn't attempt to do I/O on the device.
Allow device tables with queue_if_no_path when multipathd is not running.
Add the WWID for the specified device to the WWIDs file.
Check if the device specified in the program environment should be a path in a multipath device.
Check if the device specified in the program environment is a multipath device with usable paths. See -C.
Remove the WWID for the specified device from the WWIDs file.
Reset the WWIDs file to only include the current multipath devices.
Force new maps to use the specified policy:
One path per priority group.
All paths in one priority group.
One priority group per serial number.
One priority group per priority value. Priorities are determined by callout programs specified as a global, per-controller or per-multipath option in the configuration file.
One priority group per target node name. Target node names are fetched in /sys/class/fc_transport/target*/node_name.

Existing maps are not modified.

Number of times to retry flushing multipath devices that are in-use. The default is 0.
Update only the devmap specified by device, which is either:
A devmap name.
A path associated with the desired devmap; the path may be in one of the following formats:
/dev/sdX
major:minor

SEE ALSO

multipathd(8), multipath.conf(5), kpartx(8), udev(8), dmsetup(8), hotplug(8).

AUTHORS

multipath-tools was developed by Christophe Varoqui <christophe.varoqui@opensvc.com> and others.

2016-10-26 Linux