Configuration: Device Mapper Multipath for Linux 17714Configuration: Device MapperMultipath for LinuxOverviewThe MD3200i Series storage array uses a Linux operating system softwareframework, known as Device Mapper (DM), to enable multipath capabilitieson Linux Host Servers. The DM multipath functionality is provided by acombination of drivers and utilities. This chapter describes how to use thoseutilities to complete the process of enabling MD3200i Series storage array ona Linux system.The Device Mapper technology replaces an earlier, proprietary technology,known as MPP. MPP was used to enable multipathing for the previous MDgeneration MD3000 Series storage arrays.NOTE: The required Device Mapper software components are installed on a Linuxhost server by running the MD3200i Series resource media installation program onthe server, and selecting either the Full or Host install option. For detailedinstallation procedures please refer to the Dell PowerVault MD3200i and MD3220istorage arrays Deployment Guide.Benefits of using DM Multipath include:• Detects path failure and re-routes I/O to other available paths• Revalidates failed paths after path restoration• Utilizes multiple available paths to maximize performance• Reconfigures path usage based on path states and error conditions• Unifies multiple device nodes into a single logical multipath device node• Indentifies a new multipathed LU and automatically configures a newmultipath node• Provides device name persistency for DM devices under /dev/mapper/
