San Design; Implementation Of Standards; General Requirements And Recommendations - Dell PS4000 Configuration Manual

4 SAN Design

An EqualLogic iSCSI SAN can be operated in any network that supports the industry standards and IP
subnet design guidelines described in this section. Because of this flexibility, there are many network
design and configuration choices that can affect SAN performance. The following sections provide
details related to network design and configuration to support the use of an EqualLogic SAN.

4.1 Implementation of Standards

EqualLogic SANs are based on industry standards. The following standards are required to support all
host to target communications and member to member communications:

IETF Standards
IETF RFC1122 ―Requirements for Internet Hosts – Communications Layers‖
o
IETF RFC1123 ―Requirements for Internet Hosts – Application and Support‖
o
IETF RFC3270 ―Internet Small Computer Systems Interface (iSCSI)‖
o

IEEE Standards
802.1
o
802.3
o
iSNS Support
An Internet Storage Name Service
of group members by dynamically updating information about the iSCSI target names for group
volumes. Once the IP address of an iSNS server is entered in an iSCSI initiator's configuration utility,
the setting is persistent across initiator sessions. A PS Series group can be configured to register with
up to three iSNS servers.
Note: Starting with Firmware V4.1.4, volume and snapshot identifiers are no longer
automatically published to iSNS servers. This applies to new volumes and snapshots as well
as volumes and snapshots that existed before the group was upgraded to V4.1.4.

4.2 General Requirements and Recommendations

For EqualLogic PS Arrays, the following general SAN design requirements apply:

For all members (arrays) in a given SAN Group all ports should be connected to the same
subnet. This allows the arrays to communicate with each other as a group of peer members.
The arrays must be in the same subnet as the group's ―well known‖ IP address.
Note: Hosts can be in a different subnet as long as those hosts have layer 3 routing available
to the subnet containing the arrays and the group's well known IP address.

Rapid Spanning Tree Protocol must be enabled if the SAN infrastructure has more than two
switches in a non-stacked configuration.
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The Internet Storage Name Service (iSNS) specification:
Dell EqualLogic Configuration Guide v11.3
3
(iSNS) server can support discovery, management and configuration
http://tools.ietf.org/html/rfc4171
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