Configuring Multipath on Centos7

Device Mapper Multipathing (DM-Multipath) is a native multipathing in Linux, Device Mapper Multipathing (DM-Multipath) can be used for Redundancy and to Improve the Performance. It aggregates or combines the multiple I/O paths between Servers and Storage, so it creates a single device at the OS Level. Typically, the storage area network (SAN) topology is set up in a redundant way. That means that the connection your server has to the storage will survive a failure of a controller, disk, network connection, or anything on the SAN. It also means that if you’re connecting to the SAN over multiple connections, the logical unit numbers (LUNs) on the SAN will be presented multiple times. If there are four different paths to your LUNs, on the connected node, you’ll see /dev/sda, /dev/sdb, and /dev/sdc, as well as /dev/sdd, all referring to the same device. As all of the /dev/sd devices are bound to a specific path, you shouldn’t connect to either of them. If the specific path you’re connected to at that moment would fail, you would lose your connection. That is why multipath was invented.

To Keep Everything simple I have created a mind-map for this configuration
-the map should be read anti-clockwise starting from top left

If you do not need to edit the /etc/multipath.conf file, you can set up DM-Multipath for a basic failover configuration by running the following command. This command enables the multipath configuration file and starts the multipathd daemon.

# mpathconf --enable --with_multipathd y

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