Novell INTERNET STORAGE NAME SERVICE 1.0 -... User manual

Novell
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novdocx (en) 6 April 2007
iSNS for Linux Administration Guide
Internet Storage Name Service
1.0
November 14, 2007
NOVELL INTERNET STORAGE NAME
SERVICE ADMINISTRATION GUIDE

novdocx (en) 6 April 2007
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Contents 5
Contents
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About This Guide 7
1 iSNS for Linux Overview 9
1.1 How iSNS Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.2 Benefits of iSNS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.3 What's Next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2 iSNS for Linux Installation and Setup 11
2.1 Installing iSNS for Linux. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2 Setting Up iSNS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.1 Configuring iSCSI Targets and Initiators to Use iSNS. . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.2 Starting iSNS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.3 Creating iSNS Discovery Domains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.4 Creating iSNS Discovery Domain Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.5 Adding iSCSI Nodes to a Discovery Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.6 Adding Discovery Domains to a Discovery Domain Set . . . . . . . . . . . . . . . . . . . . . . 13
2.2.7 Setting Up the iSCSI Initiator to Use the iSNS Server . . . . . . . . . . . . . . . . . . . . . . . 14
A Documentation Updates 15
A.1 November 14, 2007 (Updates) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
A.1.1 Setting Up iSNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

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About This Guide
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7
About This Guide
This guide includes information on the Novell®Internet Storage Name Service (iSNS) for Linux*,
which provides management of iSCSI target and initiator resources for automatic discovery.
The following topics are included in this documentation:
Chapter 1, “iSNS for Linux Overview,” on page 9
Chapter 2, “iSNS for Linux Installation and Setup,” on page 11
Audience
This guide is intended for intended for anyone involved in installing, configuring, and managing
iSNS.
Feedback
We want to hear your comments and suggestions about this manual and the other documentation
included with this product. Please use the User Comments feature at the bottom of each page of the
online documentation, or go to www.novell.com/documentation/feedback.html and enter your
comments there.
Documentation Updates
The latest version of this iSNS Administration Guide is available on the SLES 10 Documentation
Web site (http://www.novell.com/documentation/sles10/index.html#additional).
Documentation Conventions
In Novell documentation, a greater-than symbol (>) is used to separate actions within a step and
items in a cross-reference path.
A trademark symbol (®, ™, etc.) denotes a Novell trademark. An asterisk (*) denotes a third-party
trademark.

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iSNS for Linux Overview
1
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9
1
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 1. iSNS facilitates the automated discovery,
management, and configuration of iSCSI devices on a TCP/IP network. iSNS provides intelligent
storage discovery and management services comparable to those found in Fibre Channel networks.
This overview contains the following sections:
Section 1.1, “How iSNS Works,” on page 9
Section 1.2, “Benefits of iSNS,” on page 10
Section 1.3, “What's Next,” on page 10
1.1 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 initiator 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 login 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 logins and by limiting the amount of time
each host spends establishing login relationships. This lets you control and simplify the number of
targets and initiators that have access to each other.
Figure 1-1 iSNS Discovery Domains and Discovery Domain Sets
iSNS clients initiate transactions with iSNS servers using the iSNS protocol. They then register
device attribute information in a common discovery domain, download information about other
Discovery
Domain
Set
Discovery
Domain
Target Target TargetInitiator Initiator
Nodes
Target and
Initiator

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registered clients, and receive asynchronous notification of events that occur in their discovery
domain.
iSNS servers respond to iSNS protocol queries and requests made by iSNS clients using the iSNS
protocol. iSNS servers initiate iSNS protocol state change notifications and store properly
authenticated information submitted by a registration request in an iSNS database.
1.2 Benefits of iSNS
Some of the benefits provided by iSNS for Linux include:
Provides an information facility for registration, discovery, and management of networked
storage assets.
Integrates with the DNS infrastructure
Provides access control for registered targets and initiators
Consolidates registration, discovery, and management of iSCSI storage
Simplifies storage management implementations.
Improves scalability compared to other discovery methods.
An example of the benefits iSNS provides can be better understood through the following scenario:
Suppose you have a company that has 100 iSCSI initiators and 100 iSCSI targets. Depending on
your configuration, all iSCSI initiators could potentially try to discover and connect to any of the
100 iSCSI targets. This could create a discovery and connection nightmare. By grouping initiators
and targets into discovery domains, you can prevent iSCSI initiators in one department from
discovering and connecting to the iSCSI targets in another department. The result is that the iSCSI
initiators in a specific department can only discover those iSCSI targets that are part of the
department’s Discovery Domain.
1.3 What's Next
For information on installing and configuring iSNS, see iSNS for Linux Installation and Setup.