Scroll to navigation

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

-v level
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.
-h
Print usage text.
-d
Dry run, do not create or update devmaps.
-l
Show the current multipath topology from information fetched in sysfs and the device mapper.
-ll
Show the current multipath topology from all available information (sysfs, the device mapper, path checkers ...).
-f
Flush a multipath device map specified as parameter, if unused.
-F
Flush all unused multipath device maps.
-t
Display the currently used multipathd configuration.
-T
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.
-r
Force devmap reload.
-i
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.
-B
Treat the bindings file as read only.
-b bindings_file
Set user_friendly_names bindings file location. The default is /etc/multipath/bindings.
-c
Check if a block device should be a path in a multipath device.
-C
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.
-q
Allow device tables with queue_if_no_path when multipathd is not running.
-a
Add the WWID for the specified device to the WWIDs file.
-u
Check if the device specified in the program environment should be a path in a multipath device.
-U
Check if the device specified in the program environment is a multipath device with usable paths. See -C.
-w
Remove the WWID for the specified device from the WWIDs file.
-W
Reset the WWIDs file to only include the current multipath devices.
-p policy
Force new maps to use the specified policy:
failover
One path per priority group.
multibus
All paths in one priority group.
group_by_serial
One priority group per serial number.
group_by_prio
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.
group_by_node_name
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.
-R retries
Number of times to retry flushing multipath devices that are in-use. The default is 0.
device
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