1MULTIPATH(8)             Linux Administrator's Manual             MULTIPATH(8)
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NAME

6       multipath - Device mapper target autoconfig
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SYNOPSIS

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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DESCRIPTION

14       multipath  is used to detect multiple paths to devices for fail-over or
15       performance reasons and coalesces them
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OPTIONS

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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NOTES

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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SEE ALSO

88       udev(8), dmsetup(8) hotplug(8)
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AUTHORS

91       multipath   was  developed  by  Christophe  Varoqui,  <christophe.varo‐
92       qui@free.fr> and others.
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96                                   July 2006                      MULTIPATH(8)
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