1MULTIPATH(8) System Manager's Manual MULTIPATH(8)
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6 multipath - Device mapper target autoconfig.
7
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]
13
15 multipath is used to detect and coalesce multiple paths to devices, for
16 fail-over or performance reasons.
17
19 -v level
20 Verbosity, print all paths and multipaths:
21 0 No output.
23 1 Print the created or updated multipath names
25 only, for use to feed other tools like kpartx.
26 2 + Print all info: detected paths, coalesced paths
28 (ie multipaths) and device maps.
29 -h Print usage text.
31 -d Dry run, do not create or update devmaps.
33 -l Show the current multipath topology from information fetched in
35 sysfs and the device mapper.
36 -ll Show the current multipath topology from all available informa‐
38 tion (sysfs, the device mapper, path checkers ...).
39 -f Flush a multipath device map specified as parameter, if unused.
41 -F Flush all unused multipath device maps.
43 -t Display the currently used multipathd configuration.
45 -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 -r Force devmap reload.
51 -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 -B Treat the bindings file as read only.
61 -b bindings_file
63 Set user_friendly_names bindings file location. The default is
64 /etc/multipath/bindings.
65 -c Check if a block device should be a path in a multipath device.
67 -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 -q Allow device tables with queue_if_no_path when multipathd is not
73 running.
74 -a Add the WWID for the specified device to the WWIDs file.
76 -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 -U Check if the device specified in the program environment is a
82 multipath device with usable paths. See -C.
83 -w Remove the WWID for the specified device from the WWIDs file.
85 -W Reset the WWIDs file to only include the current multipath
87 devices.
88 -p policy
90 Force new maps to use the specified policy:
91 failover One path per priority group.
93 multibus All paths in one priority group.
95 group_by_serial
97 One priority group per serial number.
98 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 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 Existing maps are not modified.
111 -R retries
113 Number of times to retry flushing multipath devices that are in-
114 use. The default is 0.
115 device Update only the devmap specified by device, which is either:
117 · A devmap name.
119 · A path associated with the desired devmap; the path
121 may be in one of the following formats:
122 · /dev/sdX
124 · major:minor
126
128 multipathd(8), multipath.conf(5), kpartx(8), udev(8), dmsetup(8), hot‐
129 plug(8).
130
132 multipath-tools was developed by Christophe Varoqui <christophe.varo‐
133 qui@opensvc.com> and others.
134Linux 2016-10-26 MULTIPATH(8)