Technical information

42 EqualLogic Configuration Guide | Version 15.2 | August 2014
9 Building a high-availability SAN
Designing a redundant SAN requires the availability of redundant NICs or HBAs on each server. A
redundant NIC configuration on the server requires at least two NICs.
The information provided here does not address all of the possible variations in a SAN.
All information is presented using a set of basic reference designs that make the following assumptions:
 The SAN network is physically isolated from all other network traffic
 The examples are based on best practice design principles.
 Unless otherwise stated, all reference designs will provide end-to-end host to volume redundant
paths
 A minimal number of switches will be illustrated to allow for the design concept to be understood.
Actual implementations will vary depending on your network infrastructure requirements.
 If sharing physical switches with other non-SAN traffic, we assume all switches are VLAN capable.
Note: The PS4110 and PS6110 PS Series Arrays do not support dual speed connectivity. They are not
designed to support the auto-negotiate feature. The connectivity must be 10Gb ONLY - This is the only
supported configuration.
9.1 Multi-path I/O
There are generally two types of multi-path access methods for communicating from a host to an external
device. For general networking communications, the preferred method of redundant connections is the
teaming of multiple NICs into a single, virtual network connection entity. For storage, the preferred
method of redundant connection is the use of Multi-Path IO (MPIO). Though some storage solution can
and do support either method for iSCSI connectivity, EqualLogic requires the use of MPIO to enable
multiple NIC/HBA connections to be utilized for access to an EqualLogic SAN.
The MPIO ToolKits, for available Operating Systems, can be found at the link below: (for example, the Host
Integration ToolKit for Microsoft Windows and Linux or the Multipath Extension Module for VMware ESXi).
https://eqlsupport.dell.com/support/download.aspx
Click on the Host Integration ToolKit for your Operating System.
Note: EqualLogic does not support NIC teaming on interfaces connected to the SAN.
9.1.1 EqualLogic MPIO Requirements
The following host port requirements must be met to use MPIO with EqualLogic SANs:
 At least two Ethernet ports are required on each host.
 The host operating system must have a supported MPIO driver or service available.
 The ports used for MPIO cannot be “teamed” to other ports.
 The ports must be the same speed