1MULTIPATH(8) Linux Administrator's Manual MULTIPATH(8)
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6 multipath - Device mapper target autoconfig
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9 multipath [-v verbosity] [-b bindings_file] [-d]
10 [-h|-l|-ll|-f|-t|-F|-B|-c|-q|-r|-r|-a|-A|-w|-W] [-p failover|multi‐
11 bus|group_by_serial|group_by_prio|group_by_node_name] [device]
12
14 multipath is used to detect multiple paths to devices for fail-over or
15 performance reasons and coalesces them
16
18 -v level
19 verbosity, print all paths and multipaths
20 0 no output
22 1 print the created or updated multipath names
24 only, for use to feed other tools like kpartx
25 2 + print all info : detected paths, coalesced
27 paths (ie multipaths) and device maps
28 -h print usage text
30 -d dry run, do not create or update devmaps
32 -l show the current multipath topology from information fetched in
34 sysfs and the device mapper
35 -ll show the current multipath topology from all available informa‐
37 tion (sysfs, the device mapper, path checkers ...)
38 -f flush a multipath device map specified as parameter, if unused
40 -F flush all unused multipath device maps
42 -t print internal hardware table to stdout
44 -r force devmap reload
46 -i ignore wwids file when processing devices
48 -B treat the bindings file as read only
50 -b bindings_file
52 set user_friendly_names bindings file location. The default is
53 /etc/multipath/bindings
54 -c check if a block device should be a path in a multipath device
56 -q allow device tables with queue_if_no_path when multipathd is not
58 running
59 -a add the wwid for the specified device to the wwids file
61 -A add wwids from any kernel command line mpath.wwid parameters to
63 the wwids file
64 -w remove the wwid for the specified device from the wwids file
66 -W reset the wwids file to only include the current multipath
68 devices
69 -T tm:valid
71 check if tm matches the multipathd configuration timestamp value
72 from /run/multipathd/timestamp If so, return success if valid is
73 1. Otherwise, return failure. If the timestamp doesn't match
74 continue with multipath execution. This option is designed to
75 be used with -c by the udev rules.
76 -p policy
78 force new maps to use the specified policy:
79 failover 1 path per priority group
81 multibus all paths in 1 priority group
83 group_by_serial
85 1 priority group per serial
86 group_by_prio
88 1 priority group per priority value. Priorities
89 are determined by callout programs specified as
90 a global, per-controller or per-multipath
91 option in the configuration file
92 group_by_node_name
94 1 priority group per target node name. Target
95 node names are fetched in /sys/class/fc_trans‐
96 port/target*/node_name.
97 Existing maps are not modified.
99 device update only the devmap the path pointed by device is in. device
101 is in the /dev/sdb (as shown by udev in the $DEVNAME variable)
102 or major:minor format. device may alternatively be a multipath
103 mapname
104
106 multipathd(8), multipath.conf(5), kpartx(8), udev(8), dmsetup(8) hot‐
107 plug(8)
108
110 multipath was developed by Christophe Varoqui, <christophe.varo‐
111 qui@opensvc.com> and others.
112 July 2006 MULTIPATH(8)