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]  [-p failover|multi‐
10       bus|group_by_serial|group_by_prio|group_by_node_name] [device]
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DESCRIPTION

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

17       -v  level
18              verbosity, print all paths and multipaths
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20                   0           no output
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22                   1           print  the  created  or updated multipath names
23                               only, for use to feed other tools like kpartx
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25                   2 +         print all  info  :  detected  paths,  coalesced
26                               paths (ie multipaths) and device maps
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28       -h     print usage text
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30       -d     dry run, do not create or update devmaps
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32       -l     show  the current multipath topology from information fetched in
33              sysfs and the device mapper
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35       -ll    show the current multipath topology from all available  informa‐
36              tion (sysfs, the device mapper, path checkers ...)
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38       -f     flush a multipath device map specified as parameter, if unused
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40       -F     flush all unused multipath device maps
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42       -p policy
43              force maps to specified policy:
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45                   failover    1 path per priority group
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47                   multibus    all paths in 1 priority group
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49                   group_by_serial
50                               1 priority group per serial
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52                   group_by_prio
53                               1 priority group per priority value. Priorities
54                               are determined by callout programs specified as
55                               a   global,   per-controller  or  per-multipath
56                               option in the configuration file
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58                   group_by_node_name
59                               1 priority group per target node  name.  Target
60                               node  names are fetched in /sys/class/fc_trans‐
61                               port/target*/node_name.
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63       device update only the devmap the path pointed by device is in.  device
64              is  in  the /dev/sdb (as shown by udev in the $DEVNAME variable)
65              or major:minor format.  device may alternatively be a  multipath
66              mapname
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NOTES

69       a  map  may  be  unused if, eg, the file system on it is not mounted or
70       there are no open file descriptors against the device file, as in a raw
71       device.
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SEE ALSO

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

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