All of the components required for DM-MP are included on the installation media.
Overview of migrating to the Linux DM-MP multipath driver
Because the MPP/RDAC driver is no longer available with SANtricity 11.25 or later, you must migrate to the Linux Device Mapper Multipath (DM-MP) driver. This procedure results in use of the Linux DM-MP (Kernel 3.9 or earlier) host type that uses the scsi_dh_rdac device handler. If you have already migrated to the DM-MP multipath driver in SANtricity 11.25 or later, you do not need to perform these steps.
Setting up the multipath.conf file
The multipath.conf file is the configuration file for the multipath daemon, multipathd. The multipath.conf file overrides the built-in configuration table for multipathd. Any line in the file whose first non-white-space character is # is considered a comment line. Empty lines are ignored.
Setting up DM-MP for large I/O blocks
When a single I/O operation requests a block larger than 512 KB, this is considered to be a large block. You must tune certain parameters for a device that uses Device Mapper Multipath (DM-MP) for the device to perform correctly with large I/O blocks. Parameters are usually defined in terms of blocks in the kernel, and are shown in terms of kilobytes to the user. For a normal block size of 512 bytes, simply divide the number of blocks by 2 to get the value in kilobytes.
Using the device mapper devices
Multipath devices are created under /dev/ directory with the prefix dm- . These devices are the same as any other block devices on the host. To list all of the multipath devices, run the multipath –ll command.