Install Guide

Overview
VMware vSphere provides the Pluggable Storage Architecture (PSA), which enables you to configure multipathing for high availability and
increased performance. The modular design of the architecture accepts third-party multipathing plugins that enable enhanced
functionality specific to storage device models
The Dell EqualLogic Multipathing Extension Module (MEM) provides the following enhancements to the existing VMware multipathing
functionality:
Increased bandwidth
Reduced network latency
Automatic connection management
Automatic load balancing across multiple active paths
Topics:
Dell EqualLogic MEM Architecture
Dell EqualLogic MEM Configuration Model
Determining the Number of Sessions
Related Documentation
Dell EqualLogic MEM Architecture
The Dell EqualLogic MEM consists of:
The EqualLogic kernel mode Path Selection Plugin (PSP) driver — A kernel-mode plugin that the VMware Native Multipathing Plugin
(NMP) uses to select the best path for each I/O to EqualLogic storage devices.
The EqualLogic Host Connection Manager (EHCM) — A user-mode process that runs in a CIM provider and manages the iSCSI
sessions to EqualLogic storage devices.
The PSP provides load-balancing capabilities that enable you to maximize I/O throughput. The PSP uses its knowledge of the distributed
nature of volumes on the PS Series group and least queue depth to route each I/O packet on the most optimal path to the volume.
EHCM simplifies management by creating the appropriate number of sessions to an EqualLogic volume.
Dell EqualLogic MEM Configuration Model
Figure 1. Dell EqualLogic MEM Logical Path Configuration shows the logical path configuration that the MEM uses.
1
6 Overview