Chapter 5. DM-Multipath Administration and Troubleshooting
26
the device mapper. The
-ll
option displays the information the
-l
displays in addition to all other
available components of the system.
When displaying the multipath configuration, there are three verbosity levels you can specify with the
-v
option of the
multipath
command. Specifying
-v0
yields no output. Specifying
-v1
outputs the
created or updated multipath names only, which you can then feed to other tools such as
kpartx
.
Specifying
-v2
prints all detected paths, multipaths, and device maps.
The following example shows the output of a
multipath -l
command.
#
multipath -1
mpath1 (3600d0230003228bc000339414edb8101)
[size=10 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=1][active]
\_ 2:0:0:6 sdb 8:16 [active][ready]
\_ round-robin 0 [prio=1][enabled]
\_ 3:0:0:6 sdc 8:64 [active][ready]
5.7. Multipath Command Options
Table 5.1, “Useful
multipath
Command Options”
describes some options of the
multipath
command that you may find useful.
Option
Description
-l
Display the current multipath configuration gathered from
sysfs
and
the device mapper.
-ll
Display the current multipath configuration gathered from
sysfs
, the
device mapper, and all other available components on the system.
-f
device
Remove the named multipath device.
-F
Remove all multipath devices.
Table 5.1. Useful
multipath
Command Options
5.8. Determining Device Mapper Entries with the dmsetup
Command
You can use the
dmsetup
command to find out which device mapper entries match the multipathed
devices.
The following command displays all the device mapper devices and their major and minor numbers.
The minor numbers determine the name of the dm device. For example, a minor number of 3
corresponds to the multipathed device
/dev/dm-3
.
#
dmsetup ls
mpath2 (253, 4)
mpath4p1 (253, 12)
mpath5p1 (253, 11)
mpath1 (253, 3)