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] [-d] [-h|-l|-ll|-f|-F|-B|-a|-w|-W]
10 [-p failover|multibus|group_by_serial|group_by_prio|group_by_node_name]
11 [device]
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14 multipath is used to detect multiple paths to devices for fail-over or
15 performance reasons and coalesces them
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18 -v level
19 verbosity, print all paths and multipaths
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21 0 no output
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23 1 print the created or updated multipath names
24 only, for use to feed other tools like kpartx
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26 2 + print all info : detected paths, coalesced
27 paths (ie multipaths) and device maps
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29 -h print usage text
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31 -d dry run, do not create or update devmaps
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33 -l show the current multipath topology from information fetched in
34 sysfs and the device mapper
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36 -ll show the current multipath topology from all available informa‐
37 tion (sysfs, the device mapper, path checkers ...)
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39 -f flush a multipath device map specified as parameter, if unused
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41 -F flush all unused multipath device maps
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43 -r force multipath to reload the device maps
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45 -B treat the bindings file as read only
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47 -c check if the specified path device is or should be multipathed
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49 -a add the wwid for the specified device to the wwids file
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51 -w remove the wwid for the specified device from the wwids file
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53 -W reset the wwids file to only include the current multipath
54 devices
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56 -p policy
57 force maps to specified policy:
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59 failover 1 path per priority group
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61 multibus all paths in 1 priority group
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63 group_by_serial
64 1 priority group per serial
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66 group_by_prio
67 1 priority group per priority value. Priorities
68 are determined by callout programs specified as
69 a global, per-controller or per-multipath
70 option in the configuration file
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72 group_by_node_name
73 1 priority group per target node name. Target
74 node names are fetched in /sys/class/fc_trans‐
75 port/target*/node_name.
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77 device update only the devmap the path pointed by device is in. device
78 is in the /dev/sdb (as shown by udev in the $DEVNAME variable)
79 or major:minor format. device may alternatively be a multipath
80 mapname
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83 a map may be unused if, eg, the file system on it is not mounted or
84 there are no open file descriptors against the device file, as in a raw
85 device.
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88 udev(8), dmsetup(8) hotplug(8)
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91 multipath was developed by Christophe Varoqui, <christophe.varo‐
92 qui@free.fr> and others.
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96 July 2006 MULTIPATH(8)