Detailed instructions for use are in the User's Guide.
[. . . ] Novell assumes no responsibility for your failure to obtain any necessary export approvals. No part of this publication may be reproduced, photocopied, stored on a retrieval system, or transmitted without the express written consent of the publisher. has intellectual property rights relating to technology embodied in the product that is described in this document. In particular, and without limitation, these intellectual property rights may include one or more of the U. S. [. . . ] 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
Nodes Target and Initiator
Discovery Domain
Discovery Domain Set
Target
Initiator
Target
Target
Initiator
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
iSNS for Linux Overview
9
novdocx (en) 6 April 2007
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. 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. 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.
10
iSNS for Linux Administration Guide
novdocx (en) 6 April 2007
iSNS for Linux Installation and Setup
2
2
iSNS for Linux is included with SLES 10 SP1, but is not installed or configured by default. You must install the iSNS package modules (isns and yast2-isns modules) and configure or set up iSNS to use it. Section 2. 1, "Installing iSNS for Linux, " on page 11 Section 2. 2, "Setting Up iSNS, " on page 11
2. 1 Installing iSNS for Linux
iSNS needs to be installed on only one server on your network. To provide an added level of redundancy, you can configure iSNS to be a cluster resource that can be failed over or migrated to another server on your network. NOTE: iSNS can be installed on the same server as an iSCSI target or initiator. iSNS does not support configurations where an iSCSI target and initiator are on the same server. To install iSNS for Linux: 1 Start YaST and select Software Management. 3 Select both the isns and yast2-isns packages, then click Accept.
2. 2 Setting Up iSNS
The following sections contain information to help you set up and configure iSNS: Section 2. 2. 1, "Configuring iSCSI Targets and Initiators to Use iSNS, " on page 11 Section 2. 2. 2, "Starting iSNS, " on page 12 Section 2. 2. 3, "Creating iSNS Discovery Domains, " on page 12 Section 2. 2. 4, "Creating iSNS Discovery Domain Sets, " on page 13 Section 2. 2. 5, "Adding iSCSI Nodes to a Discovery Domain, " on page 13 Section 2. 2. 6, "Adding Discovery Domains to a Discovery Domain Set, " on page 13 Section 2. 2. 7, "Setting Up the iSCSI Initiator to Use the iSNS Server, " on page 14
2. 2. 1 Configuring iSCSI Targets and Initiators to Use iSNS
To configure iSCSI targets and initiators to use iSNS, you must edit the iSCSI configuration file on each iSCSI target and initiator server and add lines that specify the iSNS server address.
iSNS for Linux Installation and Setup
11
novdocx (en) 6 April 2007
Editing the iSCSI Target Configuration File Edit the /etc/ietd. conf file and add the following line: iSNSServer isns_server_ip_address Replace isns_server_ip_address with the IP address of the server where you installed iSNS. A commented-out section with this line might already exist in the configuration file. If this is the case, you only need to replace the sample IP address with the IP address of your iSNS server. You can create a discovery domain and add nodes to that discovery domain, but it is not active and the iSNS service does not function unless you add the discovery domain to a discovery domain set. A default discovery domain set named default DDS is automatically created when you install iSNS and the default discovery domain is automatically added to that domain set. To create a discovery domain set: 1 Start YaST and under Network Services, select iSNS Server. [. . . ] If you are an existing user, review the change entries to readily identify modified content. Refer to the publication date, which appears on the title page, to determine the release date of this guide. For the most recent version of the Novell Internet Storage Name Service Administration Guide, see the "Additional Information and Updates" section of the SLES 10 documentation Web site (http://www. novell. com/documentation/sles10/#additional). In this section, content changes appear in reverse chronological order, according to the publication date. [. . . ]