Multipath configuration on RHEL6

1. Check if you have already installed device-mapper-multipath rpm, if not then install it.

rpm -qa device-mapper-multipath

2. If /etc/multipath.conf file doesn’t exist, then copy it from /usr/share/doc/device-mapper-multipath-*

cp /usr/share/doc/device-mapper-multipath-0.4.9/multipath.conf /etc/multipath.conf

3. Find WWIDs that should be added to multipath configuration.

# scsi_id -g -u /dev/sdb
36001438009b044d90000900000780000

4. Edit the /etc/multipath.conf configuration file

defaults {
        user_friendly_names yes
        path_grouping_policy    failover
}

blacklist {
        wwid "*"
}

blacklist_exceptions {
        wwid "36001438009b044d90000900000780000"
}

multipaths {
        multipath {
                wwid                    "36001438009b044d90000900000780000"
                alias                   asm1
        }
}

5.  Add module to the Linux kernel:

modprobe dm-multipath

6. Start multipath service:

service multipathd start

7. If you have any syntax errors or any parameters that do not work in your Linux version, the following command will show:

multipath -d

8. Commit the configuration:

multipath -v2

9. The following command must find the paths , or you have a bad configuration in multipath.conf file:

multipath -ll

10. Make devices configured after a reboot:

chkconfig multipathd on

If you have made any mistakes in multipath.conf file then correct them and do  the following steps to make changes take affect :

1. edit the /etc/multipath.conf

2.  Reload the multipath service:

service multipathd reload

3.  Remove all unused multipath devices

multipath -F

4.  Check again that syntax is correct:

multipath –d

5.  Commit the changes:

multipath –v2

Note that, this configuration is very simple, but it is working also perfectly.

For more multipath options and more sophisticated configuration, see the following documentation.

About Mariami Kupatadze
Oracle Certified Master Linkedin: https://www.linkedin.com/in/mariami-kupatadze-01074722/

2 Responses to Multipath configuration on RHEL6

  1. Pedro says:

    Great … very usefulll !!! Thanks !

  2. Jimmy says:

    awesome explenation…

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