Installation guide

Note

When a multipath device is being created or modified, the path group status and the dm status

are not known. Also, the features are not always correct. When a multipath device is being listed,

the path group priority is not known.

5.2. Multipath Queries with multipath Command

You can use the -l and -ll options of the m ultipath command to display the current multipath

configuration. T he -l option displays multipath topology gathered from information in sysfs and the

device mapper. T he -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 m ultipath 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.

# mul tipath -l

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]

5.3. Multipath Command Options

Table 5.1, “Useful m ultipath Command Options” describes some options of the m ultipath

command that you may find useful.

Table 5.1. Useful m ultipath Command Options

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.

5.4. 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.

Chapter 5. DM-Multipath Administration and Troubleshooting