multipath man page

multipath — Device mapper target autoconfig.

Synopsis

multipath [-v verbosity] [-b bindings_file] [-d] [-h|-l|-ll|-f|-t|-F|-B|-c|-q|-r|-i|-a|-A|-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

Print internal hardware table to stdout.

-r

Force devmap reload.

-i

Ignore WWIDs file when processing devices.

-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.

-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. -A add wwids from any kernel command line mpath.wwid parameters to the wwids file

-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.

Referenced By

kpartx(8), mpathconf(8), mpathpersist(8), multipath.conf(5), multipathd(8).

2016-10-26 Linux