3 Isns For Linux Overview; How Isns Works - Novell LINUX ENTERPRISE SERVER 10 SP2 - INSTALLATION AND ADMINISTRATION Installation Manual

13
iSNS for Linux Overview
Storage area networks (SANs) can contain many disk drives that are dispersed across
complex networks. This can make device discovery and device ownership difficult.
iSCSI initiators must be able to identify storage resources in the SAN and determine
whether they have access to them.
Internet Storage Name Service (iSNS) is a standards-based service that is available
with SUSE Linux Enterprise Server (SLES) 10 Support Pack 2. iSNS facilitates the
automated discovery, management, and configuration of iSCSI devices on a TCP/IP
network. iSNS provides intelligent storage discovery and management services compa-
rable to those found in Fibre Channel networks.

13.1 How iSNS Works

For an iSCSI initiator to discover iSCSI targets, it needs to identify which devices in
the network are storage resources and what IP addresses it needs to access them. A
query to an iSNS server returns a list of iSCSI targets and the IP addresses that the ini-
tiator has permission to access.
Using iSNS, you create iSNS discovery domains and discovery domain sets. You then
group or organize iSCSI targets and initiators into discovery domains and group the
discovery domains into discovery domain sets. By dividing storage nodes into domains,
you can limit the discovery process of each host to the most appropriate subset of targets
registered with iSNS, which allows the storage network to scale by reducing the number
of unnecessary discoveries and by limiting the amount of time each host spends estab-
iSNS for Linux Overview 283