1MULTIPATH(8)                System Manager's Manual               MULTIPATH(8)
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NAME

6       multipath - Device mapper target autoconfig.
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SYNOPSIS

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

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

19       -v level
20              Verbosity, print all paths and multipaths:
21
22                   0           No output.
23
24                   1           Print  the  created  or updated multipath names
25                               only, for use to feed other tools like kpartx.
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27                   2 +         Print all info: detected paths, coalesced paths
28                               (ie multipaths) and device maps.
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30       -h     Print usage text.
31
32       -d     Dry run, do not create or update devmaps.
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34       -l     Show  the current multipath topology from information fetched in
35              sysfs and the device mapper.
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37       -ll    Show the current multipath topology from all available  informa‐
38              tion (sysfs, the device mapper, path checkers ...).
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40       -f     Flush a multipath device map specified as parameter, if unused.
41
42       -F     Flush all unused multipath device maps.
43
44       -t     Display the currently used multipathd configuration.
45
46       -T     Display  the  currently  used multipathd configuration, limiting
47              the output to those devices actually present in the system. This
48              can be used a template for creating multipath.conf.
49
50       -r     Force devmap reload.
51
52       -i     Ignore  WWIDs  file  when processing devices. If find_multipaths
53              strict or find_multipaths no is set in multipath.conf, multipath
54              only  considers  devices that are listed in the WWIDs file. This
55              option overrides that behavior. For other values of  find_multi‐
56              paths,  this  option  has  no  effect.  See  the  description of
57              find_multipaths in multipath.conf(5).  This option  should  only
58              be used in rare circumstances.
59
60       -B     Treat the bindings file as read only.
61
62       -b bindings_file
63              Set  user_friendly_names bindings file location.  The default is
64              /etc/multipath/bindings.
65
66       -c     Check if a block device should be a path in a multipath device.
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68       -C     Check if a multipath device has usable paths. This can  be  used
69              to  test whether or not I/O on this device is likely to succeed.
70              The command itself doesn't attempt to do I/O on the device.
71
72       -q     Allow device tables with queue_if_no_path when multipathd is not
73              running.
74
75       -a     Add the WWID for the specified device to the WWIDs file.
76
77       -u     Check  if the device specified in the program environment should
78              be a path in a multipath device.  -A add wwids from  any  kernel
79              command line mpath.wwid parameters to the wwids file
80
81       -U     Check  if  the  device specified in the program environment is a
82              multipath device with usable paths. See -C.
83
84       -w     Remove the WWID for the specified device from the WWIDs file.
85
86       -W     Reset the WWIDs file  to  only  include  the  current  multipath
87              devices.
88
89       -p policy
90              Force new maps to use the specified policy:
91
92                   failover    One path per priority group.
93
94                   multibus    All paths in one priority group.
95
96                   group_by_serial
97                               One priority group per serial number.
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99                   group_by_prio
100                               One  priority group per priority value. Priori‐
101                               ties are determined by callout programs  speci‐
102                               fied  as a global, per-controller or per-multi‐
103                               path option in the configuration file.
104
105                   group_by_node_name
106                               One priority group per target node name. Target
107                               node  names are fetched in /sys/class/fc_trans‐
108                               port/target*/node_name.
109
110              Existing maps are not modified.
111
112       -R retries
113              Number of times to retry flushing multipath devices that are in-
114              use. The default is 0.
115
116       device Update only the devmap specified by device, which is either:
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118                   ·      A devmap name.
119
120                   ·      A  path associated with the desired devmap; the path
121                          may be in one of the following formats:
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123                               ·      /dev/sdX
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125                               ·      major:minor
126

SEE ALSO

128       multipathd(8), multipath.conf(5), kpartx(8), udev(8), dmsetup(8),  hot‐
129       plug(8).
130

AUTHORS

132       multipath-tools  was  developed by Christophe Varoqui <christophe.varo‐
133       qui@opensvc.com> and others.
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137Linux                             2016-10-26                      MULTIPATH(8)
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