Dell MD3220, MD3200 owner manual Configuration Device Mapper Multipath for Linux, 167

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Configuration: Device Mapper Multipath for Linux

Overview

The MD3200 Series storage array uses a Linux operating system software framework, known as Device Mapper (DM), to enable multipath capabilities on Linux Host Servers. The DM multipath functionality is provided by a combination of drivers and utilities. This chapter describes how to use those utilities to complete the process of enabling MD3200 Series storage array on a Linux system.

The Device Mapper technology replaces an earlier, proprietary technology, known as MPP. MPP was used to enable multipathing for the previous MD generation MD3000 Series storage arrays.

NOTE: The required Device Mapper software components are installed on a Linux host server by running the MD3200 Series Resource media installation program on the server, and selecting either the Full or Host install option. For detailed installation procedures please refer to the Dell PowerVault MD3200 and MD3220 storage 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 new multipath node

•Provides device name persistency for DM devices under /dev/mapper/

Configuration: Device Mapper Multipath for Linux

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