Essential Guide to Storage Area Networks, The

Description

• Copyright 2002
• Dimensions: K
• Pages: 624
• Edition: 1st

• Book
• ISBN-10: 0-13-093575-1
• ISBN-13: 978-0-13-093575-5

• The up-to-the-minute SAN guide for every decision-maker
• Concepts, standards, applications, vendors, ROI, and much more
• Planning, design, architecture, deployment, testing, performance, maintenance, and more
• In-depth coverage of SAN applications in high-availability mission-critical systems
• IP-based SANs and other emerging technologies

Reliable, cost-effective SANs: an up-to-the-minute briefing for every decision-maker.

SANs enable companies to manage accelerating amounts of data far more effectively, but their reputation for complexity has deterred many companies from deploying them. Now, there's a readable, up-to-the-minute guidebook designed to help business and IT professionals understand SAN technology, make intelligent decisions, and derive maximum business advantage from SANs—starting right now. Leading network consultant John Vacca covers the entire SAN lifecycle, from planning and strategy to implementation and day-to-day administration. Coverage includes:

• SANs: what they are and what they offer
• Debunking the Top 5 SAN myths
• Comparing today's leading approaches: advantages, disadvantages, and tradeoffs
• The SAN vendor community-including the newest SAN service providers
• IP-based SANs and other emerging standards—and what they mean to you
• Practical techniques for cost-justifying, planning, and designing SANs
• Maximizing scalability and availability
• In-depth deployment coverage: installation, testing, rollout, and performance certification
• Day-to-day management and maintenance
• Next-generation SAN applications—including virtual SANs for mission-critical Web applications
• 6 valuable appendices: product lists, vendor lists, streaming SAN case study, and much more

Storage has never been more critical to your success—and by 2005 it may account for up to 70% of your IT budget. No storage technology offers more promise than SANs. Now's the time to understand them, and this is the book: The Essential Guide to Storage Area Networks.

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Extras

Related Articles

SAN Installation and Deployment

Types of SAN Technology

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Sample Content

Online Sample Chapter

SANs Fundamentals

Table of Contents

Foreword.


Introduction.


Importance of Storage.


Value of Data.


Enterprise Core Competency.


Pros and Cons of Storage.

The Pros. The Cons.

Multiple Data Storage Options.


Managing the Arsenal.


Growing Storage Staff.


Who's Using SANs?


Who This Book is For.


What's So Special About This Book?


Part I: Overview of SANs Technology.


Part II: Designing SANs.


Part III: Planning for SANs.


Part IV: Installing and Deploying SANs.


Part V: Maintaining the SANs.


Part VI: SAN Solutions and Future Directions.


Part VII: Appendices.


Conventions.


Acknowledgments.

I. OVERVIEW OF SANS TECHNOLOGY.

SANs Fundamentals.

But What is a SAN—Really? Network Attached Storage (NAS). SAN Attached Storage (SAS). SAN Interfaces. SAN Interconnects. SAN Fabrics. Building a SAN. Why Are SANs Important? SAN Applications. Types of SAN Operating Systems Software and Hardware Components. Sharing Data in a SAN. The Case for SAN Hardware. SAN Market Demand and Projections by Region and Country. Evolution of the SAN Market. The Value of Information. The Business Information Landscape Today. Preparing for Storage Area Networking. The Challenge of Implementing SAN Technology. The Storage Networking Management Vision. From Here. End Notes.

Types of SAN Technology.

FC-AL: A First Step. SAN Setbacks. Technology and Configuration. High Scalability and Flexibility. Web Service Scaling Factors. Current Web Server Practice. Storage in the Web Server Plant. Revisiting the SAN. SANs for Web Servers: A Scalable Alternative. Technology Platform, Techniques, and Alternatives. How the GTA Did It. Scenarios. Other Scenarios. Breaking Tradition in Video Distribution. Purely Analog Video. The Introduction of Digital to Video. The Video Creation and Manipulation Workstation. A Faster Network. Push versus Pull. SANs in Video. SAP R/3 Storage Management. Environment Setup. Split Mirror Backup. Split Mirror Backup Process. Process Automation. Suspension of Application Writes. Recovery. From Here. End Notes.

Standards.

Like Ethernet, SANs Standards Are Evolving. A Phased Approach. Getting to the Third Phase. Other Players. The Future of SAN Standards. From Here. End Notes.

Types of Vendor and SANs Service Providers.

SAN Self-Service. The Interoperability Labs. The Turnkey Solution. Service Provider Outsourcing. Multiple Computer Platforms High-Speed Data Sharing. Deficiency of LAN Solutions. The SAN Revolution. True SAN-Based Data Sharing. The Future Is Sharing. Indirect Channel Opportunity. The Changing Role of the Channel. Drivers of Storage Market Growth. Identifying and Creating Opportunities in the SAN Market. Storage Suppliers Respond to Growing Customer Demand. Sharing Information. SANs Are Not a New Technology. Translating SANs into Opportunity for Partners. Business Value of SAN. Overcoming Users' Concerns about SANs. What SANs Mean to the Channel: Road Map for Exploiting SAN Opportunities. Building Up to SAN. Choosing a SAN Supplier. IBM Business Partners: Opportunities in Storage Area Networks—The Sum is Greater than the Whole. Multivendor Enterprise Storage Area Networks End-to-End Services. Storage Management Challenges. Networked Storage: The New Paradigm. Implementation Challenges. A Service-Driven SAN Strategy, from IBM. Storage Subsystems for Video Services. Related Work. Overview. Storage Server Requirements. Storage Subsystem Requirements. User and Storage Area Network Requirements. Software Requirements. The Basic Server Configuration. The Disk Subsystem. The Video Storage Server. Server Memory Requirements. Server Processing Requirements. Multiple Server Configurations. The Server Interconnect Problem: A Case for Fibre Channel. Is There an SSP in Your Future? From Here. End Notes.

Providing SAN Scalability and High Availability.

The Increased Need for Higher Availability. High-Level Availability Objectives. System Availability through Redundancy. Applications. Servers and Host Bus Adapters. Storage. Mirroring. Switches. Networking in the Fabric. Meshed Tree Topology for Switches. A Single Fabric with Dual Connectivity. A Dual Fabric with Dual Connectivity. Reliability Calculations for Single and Dual Fabrics. Zoning. Fabric Management. The Key to High Availability. From Here. End Notes.

II. DESIGNING SANS.

SAN Design Issues.

Fibre Channel Topologies. Customer Selection of Fibre Channel Products. Designing Storage Networks. Application Requirements. Protocol Support. Cable Plant. Distance between Devices. Number of Devices. Accommodation of Legacy Devices. Anticipated Growth. Traffic Volumes. Departmental Segmentation. Redundancy. Disaster Recovery. SNMP Management. Cost/Performance Ratio. Design It and They Will Come. SAN Story. End-User Education. SAN-to-SAN Connectivity. Cost Considerations. SAN Software. OEM Involvement. From Here. End Notes.

Cost Justification and Consideration.

Financial Impact of a SAN. Capital Savings. Backup Savings. Data Management. Justification of SAN Operating Costs. Financial Considerations and Acquisitions. Mission-Critical. The Middle Road. The Value Approach. Final Decision. Acquisitions. From Here. End Notes.

Standards Design Issues.

Designing Distributed SAN Standards. Driving Forces behind Infiniband Technology Adoption. Revolutionizing Internet Data Centers. SAN Standard Design Implications. IDC View of Infiniband. Postscript. New Storage Standards Design Issues. IP Debate Heating Up. Industry Unity over Standards? Customer Considerations. No Winning Protocol Likely. From Here. End Notes.

Architectural Design Considerations.

Traditional Captive Storage Architecture. SAN Architecture. Interface Comparison. SAN's Shared Storage versus Traditional Captive Storage. Availability/Reliability. Performance. Configuration Flexibility. Cost. From Here. End Note.

III. PLANNING FOR SANS.

Implementation of Plan Development.

Scalability. How Available Is It? Security Issues. How Easy Is Management? Minimizing Total Cost of Ownership (TCO). Thinking Strategically. Disaster Recovery Plan. Data Explosion. Platform Proliferation. Restoration is the Issue. Mirror, Mirror. No Panaceas. How to Make SANs a Reality in Your Environment with Your Infrastructure. Internet-Based Water Exchange Pours Resources into a SAN Infrastructure. Preparing for a SAN. Making the Decision for a SAN? Planning and Designing a SAN. Getting Help. Going Live with a SAN. From Here. End Notes.

Virtual Storage Area Networks Planning Techniques: Making the Web Mission-Critical.

No Standards Yet. SAN Clustering Technologies. Traditional IP Clustering and SANs. Storage Clusters. The Global File System. Shared GFS Root File Systems. Storage Clusters and Centralized Storage. SAN Virtualization Architectural Planning Guidelines. Virtualization Schemes. Selection Criteria. Back to the Choices. Ensuring that Your Storage Virtualization Doors are Never Closed. What is True Storage Virtualization? The Ability to Stripe across and Utilize All Available Space. The Ability to Centrally Manage and Share Storage. Nonvirtualized versus Virtualized Storage in the Real World. Nonvirtualized Storage and True Storage Virtualization. A Better Solution: True Storage Virtualization. From Here. End Notes.

IV. INSTALLING AND DEPLOYING SANS.

Testing Techniques.

Physical Layer Testing. Application Layer Testing. Management Layer Testing. Why Use SAN Testing? SANmark Revision “A” Test Suite. The Role of the SANmark Revision “A” Test. Other Testing Technology. From Here. End Notes.

Installation and Deployment.

Look to Your Applications. Prepare for the Future. How to Deploy a SAN. Expanding Storage the SAN Way. A Packaged Solution. Using HSM Technology. Getting Started on SAN. Start with Hubs. Link Hubs to a Fibre Channel Switch. Big Switch Phase. The Next Phase of SAN Deployment: Storage Switch Technology. What's Driving SAN Evolution? The Storage Switch: A Simple, Cost-Effective Approach to SAN Switching. Applying Storage Switch in the SAN: One-Tier SAN. Industry Validation of the Storage Switch. Putting Data to Work for E-Business in SAN Installation and Deployment. The Changing Environment. The Challenges. The Promise of SANs. From Here. End Notes.

Certification of SAN Performance.

SAN Testing and Troubleshooting. Documenting and Testing SANs. FSM Performance. Direct FSM Advantages. Scalability. Performance Results. Test Configuration. Performance Data. Certifying SAN Performance. From Here. End Notes.

V. MAINTAINING SANS.

Management of Storage Area Networks.

Data Management Solution. The Growing Need for More Efficient Information Management. The Advantages of a SAN Infrastructure. Greater Data Protection for Improved Backup and Recovery. More Efficient Utilization of IT Resources through Server and Storage Consolidation. Advanced Scalability and Manageability. Business Continuance through High Availability. Remote Disaster Recovery Capabilities. A Strategic Technology for the Future. Virtual Storage Area Networks. Requirements for Storage and Access. Possible Answer: SmartStor InfiNet. The Benefits of InfiNet. Return on Investment. Indirect Business Value: Customer Satisfaction for E-Business. How Does InfiNet Work? Fibre Channel-Arbitrated Loop: A Management Strategy. When is Management Required? Management Definitions: Simple Network Management Protocol (SNMP). General Issues in Arbitrated Loop Management. Device Management. Problem Detection. Problem Isolation. Recovery. Predictive Management. From Here. End Notes.

Ongoing Maintenance.

The Facts about SAN Software. Increasing Efficiency in the Prepress Market. The Problem of Performance. Storage Area Networks. The Power to Share. File Sharing of a LAN at the Speed of a SAN. A Mix of Operating Systems. A Slightly Different Workflow. From Here. End Notes.

Standards Development.

SAN Management Standards. Managing the Infrastructure. The Future of SAN Standards. Standards Wars: The Contenders. Standards Depend on the Customer. Two Gigabits and Beyond. From Here. End Notes.

VI. SAN SOLUTIONS AND FUTURE DIRECTIONS.

High Availability Business Systems: The Role of SANs.

The Causes of Data Unavailability. Cost Trade-offs. High Availability Objectives. The SAN. The Single Building. The Campus Cluster. The Metro Cluster. From Here. End Notes.

SAN Solutions for Considerations.

Solutions to Making a SAN Work. Making SAN Work. Enterprise SAN Solutions. SAN Solutions for Consolidation. SAN Solutions for Sharing. Share Storage, File Systems, and Files. SAN Solutions for Disaster Tolerance. Clustering to Achieve True Availability. Storage Management Solutions: The Vision. Holo-Vision Storage Management Solutions of the Future. From Here. End Notes.

Role of SANs in Computer Forensics.

Evidence Collection. Securing the Computer Evidence. Forensic Analysis. Reconstructing Past Events. Becoming a Digital Detective. Frankenstein. Beauty is More than Skin Deep. What's Going On? Looking for Things. From Here. End Notes.

Summary, Conclusions, and Recommendations.

The Storage Network behind the Server. The Problem: Limitations Loom over Surge of Data. Fibre Channel: The Open SAN Solution. High Bandwidth. Server and Storage Scalability. Modular Connectivity. High Availability and Fault Tolerance. Manageability. Ease of Integration. Total Cost of Ownership. Advanced Application Capabilities. SAN Future. Great Uses for Fibre Channel. Advancements. Service Differentiation. Return-on-Investment (ROI) Business Case. Storage Enters the Third Dimension: Where No SAN has Gone Before. Storage Goes Holographic. Advanced System from NASA. End Notes.

VII. APPENDICES.

Online Storage Management Checklist.
Powerful Administration.

Flexible File Migration. Quick Access to Data. Automated Scheduling. Advanced Diagnostics. List of Top SANs Implementation and Deployment Companies.

SAN Product Offerings.
SAN Storage.

SAN Software. End Notes. Standards for SANs.

SNIA Initiatives.

Initial Open SAN Solutions. Streamlined Customer Support. Next Steps by the SNIA. Setting a New Standard for SANs. How iSCSI Works. Development Milestones. Potential iSCSI Roadblocks. SCSI versus Fibre Channel Storage.

SCSI.

Fibre Channel. End Notes. List of Miscellaneous SAN Resources.

Fibre Channel.

Industry Associations. Miscellaneous SAN Resources. SCSI. Vendors. Enterprise Messaging. Partnerships. Storage Resource Management. Fibre Channel. Miscellaneous Announcements.

Glossary.
Index.

Preface

Introduction

The increasingly sophisticated and prolific world of IT has dramatically altered the demand for data storage and enhanced its value to the enterprise. Desktop, department, and enterprise environments have all evolved to the point where data that was once viewed as a static resource is now viewed as a mission-critical company asset. In this highly competitive environment, the IT community has come to realize how the capabilities of online storage management and the presence of a standard operating system such as Windows NT can significantly enhance data storage systems.

At the desktop level, office applications such as spreadsheets, word processors, database programs, multimedia, and imaging software have driven the most recent generation of PCs to the point where they feature hard drives with multiple gigabytes of storage and random access memory (RAM) of up to 1 gigabyte. Moving up to the department and workgroup levels, the demands on data storage have increased exponentially as users have begun working collaboratively on projects that generate terabytes of data and span not only departments and workgroups, but nations and continents.

Importance of Storage

Storage was once a peripheral—a mere feature of the server. Those days are long gone, and that's a good thing because information shouldn't always be hidden behind, or bottled up inside, a single server. It should be positioned so that it can be made quickly but securely available to other applications and/or departments within the enterprise. So, now that storage is out from behind the server's shadow, we need to recognize its true value. Here's why:

First, the value of data as a corporate asset has risen dramatically over the last few years. Maintaining its availability, integrity, and security is now a matter of life or death for many enterprises.

Second, with the advent of storage networking, data storage as an enterprise core competency has become demanding and complex. And with new technologies reaching the market at a torrid pace, it becomes harder and harder to understand and make judgments about all the alternatives.

Finally, there is currently a critical shortage of the trained staff required to manage the new enterprise storage environment. As a result, expertise in recruiting, training, and retaining storage management staff is now a vital enterprise IT function.

Value of Data

Data (translated by applications and infrastructure into information) has grown in value to the point where, for many enterprises, it is the most valuable corporate asset. It's a competitive differentiator—the underpinning of all customer-facing applications like CRM and CSM. And with the advent of the Web, it has expanded in importance to become mission-critical to the very enterprise as viewed through the portal. In this environment, storage is now the single most important IT resource for assuring:

• Data Availability
• Data Integrity
• Disaster Recoverability

Data Availability

The persistent availability of data as defined by the storage utility model which basically assures that enterprise data will always be accessible, will always be on—just like electricity. Lost access to data can be severely damaging and possibly fatal to the enterprise. For example, in a health care setting, continuous access to data could make the difference between life and death.

Data Integrity

The protection and preservation of data from corruption, loss, and outside attack is known as data integrity. Storage can also be thought of as a vault. When you retrieve data, you expect to retrieve exactly what was deposited. Storage and storage management personnel are the guardians of data.

Disaster Recoverability

The ability of storage networks and storage management applications to play a critical role in recovering from the inevitable disaster is known as disaster recoverability. Disaster scenarios include anything from the loss of a server running a critical application, to the loss of an entire data center due to fire, flood, earthquake, etc.

Enterprise Core Competency

It would be a gross oversimplification to say that storage was once a simple matter of plugging an array into a SCSI port. Then again, compared to the array of alternatives available now from FC-AL to FC Fabric, the IP derivatives and soon InfiniBand and beyond, the days of one-size-fits-all SCSI are also long gone. Data storage as an enterprise core competency is becoming exceeding complex. Here's a brief, and by no means exhaustive, list of the technologies now directly involved in or significantly touching upon data storage as covered in this book:

• Fibre Channel-Arbitrated Loop and fabric architectures
• Ethernet and IP
• Server clustering
• Data backup and restoration
• SCSI
• Wide and Metropolitan Area Networking protocols
• Bridging, routing, and switching
• Host bus adapters and drivers
• Broadband communications
• Enterprise management applications
• Database and file system architectures
• Operating systems

Pros and Cons of Storage

As companies grapple to store and protect vast (and growing) amounts of data, Storage Area Networks (SAN) are gaining momentum. A SAN is a dedicated configuration of multiple servers connected to peripheral storage devices using high-speed fiber and special routers, switches, and hubs. A SAN, usually part of an enterprise's overall computing resources, enables enterprises to consolidate data from disparate servers onto a centrally managed storage network.

Storage Area Networks offer certain key advantages over file serving and Network Attached Storage (NAS) boxes, namely improved data sharing, convenient storage expansion, remote backup and recovery, and increased uptime. But the adoption rate of SANs has been slowed by drawbacks such as high cost; interoperability of software; hardware and components; and data security concerns.

The Pros

Some companies see Storage Area Networks as a solution. The following are the pros:

• Data sharing
• Live expansion capacity
• Remote backup and recovery

Data Sharing

A SAN makes stored data available to multiple users simultaneously, without disrupting productivity. A SAN provides high-speed access to data among a number of system servers, thus enabling data to be retrieved faster when used by a large number of users. This is critical for efficient company operations and for Web storage where millions of users may need to access data.

Individual computers in a SAN see each data-storage device as a shared resource, eliminating data bottlenecks common to NAS and file serving environments. You might have 30 computers, but each one sees the storage as one big pool.

Live Expansion Capacity

A SAN allows network administrators to expand storage capacity without shutting down critical file servers. Instead, new storage devices are plugged directly into the fiber connecting the various servers to existing storage capacity. With the Internet, system administrators have to make sure their data is available all the time-and keep it safe to boot.

Remote Backup and Recovery

Since it's a separate network, a SAN enables automatic data backup, meaning IT administrators don't need to swap out backup tapes each day. Backup occurs without interrupting users on other company computer networks. One of the complaints of companies using NAS boxes is that backup traffic is consuming too much bandwidth from their production networks.

A SAN also makes data migration more manageable. Data is transported across high-speed fiber and stored on a remote server. This eliminates the need to store data on the hard drive of individual machines. It also makes data recovery easier if there's a disaster.

The Cons

The information age presents network managers with a daunting challenge: store ever-increasing amounts of business-critical data, keep it secure but accessible at high speeds to multiple users, and ensure timely, regular backup—all without increasing IT costs. The following are the cons:

• Cost
• Interoperability
• Network Security

Cost

Industry experts say a comprehensive SAN could cost hundreds of thousands of dollars, putting them beyond the reach of most small enterprises. Although a SAN could yield savings through the need for fewer IT professionals, the upfront cost intimidates most companies.

Some small- and medium-size enterprises might want to build miniature SANs, consisting of a few switches on the network, for specific departments and applications. These smaller networks give them a head start and can be expanded later to accommodate their computing needs.

Interoperability

Interoperability also is a drawback. Companies implementing a SAN often buy hardware from one company, software from another company, while a third company supplies the components needed to connect everything together. There is no overarching standard for SANs right now. A lot of vendors make a single component, so companies need to be careful that the components they select are compatible with their system.

The Storage Networking Industry Association (SNIA) of Mountain View, California, is promoting open standards to ensure that different vendors' storage networking products work compatibly. But the association concedes open standards are at least a year or two away.

Network Security

The lack of industry standards also heightens concern about security and the ability to prevent unauthorized access to data. Several workable options exist, including hybrid systems that use newer technology with more established architectures. Concern about security is the chief impediment to widespread implementation of SANs.

Security safeguards should be built into a SAN. A SAN really is no different than any other computer network. The same need to separate different kinds of machines so that they can't be used to leverage each other's access still exists.

Multiple Data Storage Options

The question for today's enterprise then, is how to manage the myriad aspects of storing and controlling this data in all of its new forms across not only the local and departmental levels, but also the divisional and corporate levels. The most obvious facet of this question is the quantity of data which must be managed and its storage requirement. However, simply providing enough storage capacity is not sufficient. Organizations today must also worry about the performance of the devices relative to the needs of the users, the cost-per-megabyte of that storage, the reliability of the different devices (which directly relates to the concept of system availability), and the ease with which an organization can ensure that data read from the storage media is identical to that written (data integrity). Different storage devices have different profiles in terms of the dimensions described in the preceding. Some are slower but cheaper, some have very high capacity but are expensive, and so on. Users, too, have different needs in terms of these same dimensions, so most enterprises today attempt to mix and match the technologies and their profiles to the specific needs of their users and their corporate bottom lines.

Planning for and architecting an online storage management approach has become a required exercise in prudent IT operations. A good online storage management plan is one that understands user profiles and makes use of the various storage alternatives. This sound approach will avoid the traps many organizations fall into, where the misapplication of technology to a storage need results in overly expensive solutions, poorly performing solutions, and, almost always, in dissatisfied customers.

Not surprisingly, storage technology is typically categorized according to the different profile dimensions described earlier: availability, capacity, performance, and economics. The availability of data is directly related to its logical location. Online data is immediately available to users. Nearline data is a term that applies to data accessible to the user after a noticeable delay, but which is still completely automated by the storage device. Because it is either no longer available or has been archived to lower-cost media, offline data (sometimes referred to as farline data) is typically housed in libraries not connected to any storage device, and which must be manually handled and mounted on the device in order to be delivered to the user. Tape libraries are good examples of offline or farline storage. In developing software systems, there is an old joke that goes One can get software systems built that are good, fast, or cheap; pick any two. Similarly, there are tradeoffs in the combinations of attributes of different systems. You can get high capacity and fast access time only at very expensive prices; you can get lower prices by sacrificing either access time or capacity, and so on.

A well-conceived online storage management system optimizes all three of these data storage categories by automatically ensuring that they each contain prioritized data available at access speeds that correlate to the data's value. This approach requires that the most frequently used data be stored on magnetic disks and available online, while less active data is maintained in nearline mode on optical disks or tape. This logical approach to prioritizing and accessing data streamlines business processes and maximizes the productivity of users, while controlling the costs of storage.

Managing the Arsenal

The good news is that there is an arsenal of storage devices that can be deployed in response to an organization's needs. In fact, most organizations typically rely on a variety of storage devices in order to satisfy all of their needs. Optical drives, jukeboxes, fixed and removable magnetic disks, tape drives, and RAID (Redundant Arrays of Independent Disks) are all deployed in varying configurations across enterprises today. The bad news is that you now have to manage a set of repositories that have very different physical and operational characteristics, and your core computer systems don't do nearly as much as you'd like them to do with regards to managing all of this.

While some other operating systems, such as UNIX, support the concept of removable devices in the core operating system, PCs and PC-based servers have implemented a storage model that presumes a single platter per drive. Device drivers are used to associate the physical devices to the operating system functions, but as long as the operating system itself only issues commands based on the notion of fixed media, additional software is needed to circumvent this problem. Therefore, any device that features removable or replaceable media, such as the popular Iomega series of drives, the newer optical 120 MB floppy media, or the older Bernoulli boxes, may be physically attached to a computer system, and the operating system will be able to identify it by a letter of the alphabet. If you can assume a system in which there are two floppy drives and two logical partitions of hard drives, the new removable drive might be referred to as drive "E." The operating system will therefore recognize the fact that there is a storage device, but since it assumes that the device is a fixed drive, it will be unaware that the drive is capable of accommodating removable media and, as such, has no mechanism for dealing with multiple, disparate volumes. Therefore, a different and supplementary set of software is needed to help applications recognize the insertion and extraction of removable media. To avoid attempts to write to a device whose media has been changed or removed, ancillary layers of software are designed to impart the concept of volumes, allowing applications to work with removable media even if the application sees each drive as a fixed device.

There are three dimensions to the problem of optimizing the plethora of storage media and technologies available on the market today. First and foremost is integrity of the stored information. The system is expected to help the user maintain that integrity through functions such as backup and restore, and the use of cyclic redundancy checks, error correcting codes, or parity checks to make sure the data is not corrupted.

Secondly, the system must help the user track and locate where the data is in logical terms and map that location to the physical devices. This entails the management of sectors and tracks on different media and the logical and methodical layout of the data across those sectors and tracks, including correlating those physical locations to a hierarchical or network filing system devised by the users. Finally, you have to be able to handle the multiple technologies used in data management, including optical, magnetic, disk, tape, and so forth.

Growing Storage Staff

There are benefits to be realized today from implementing storage networks, but because of the shortage of IT personnel with storage expertise, enterprises are hesitant to move forward. Recruiting, training, and retaining skilled storage management staff must become a core IT competency if the real benefits from storage innovation are to be realized.

Who's Using SANs?

Despite the economies of scale they offer, cost and technical complexity have kept adoption rates of SANs low. It is estimated only 6 to 11% of Fortune 500 companies have installed SANs. The rate among smaller and medium-size enterprises is much lower. In a few years, however, SANs could become a necessity for all organizations with growing data storage demands, especially given the projected growth of e-commerce.

Before SANs, the choice was to add more storage capacity to a single server. But no longer it is enough to throw more space at a storage problem. The key is to manage space more effectively, because the one thing companies can't afford to be is down.

Finally, the nature of the storage environment has changed radically in the last few years. It is now characterized by unprecedented growth in the volume of data to be managed; a quantum leap in complexity; and the sheer number of available combinations and permutations. Add to that the growing value of data to the enterprise, and the overwhelming importance of storage—storage networking becomes obvious.

Who This Book Is for

This book can be used by domestic and international system administrators, government computer security officials, network administrators, senior managers, engineers, sales engineers, marketing staff, WWW developers, military senior top brass, network designers and technicians, SAN project managers, SAN installers, LAN and PBX administrators, and other SAN personnel. This book is also valuable for systems analysts, design engineers, programmers, technical managers, and all dataprocessing, telecommunications, and office automation professionals involved in designing, configuring, or implementing SANs. In short, the book is targeted for all types of people and organizations around the globe who have responsibility for managing and maintaining the SAN service continuity of organizational systems including line and project managers; team members, consultants; software and security engineers; and other IT professionals who manage SAN cost justification, investments, and standards. Others who may find it useful are scientists, engineers, educators, top-level executives, information technology and department managers, technical staff, and the more than 900 million Internet, intranet, and extranet users around the world. Some previous experience with SAN installation is required.

What's So Special About This Book?

The Essential Guide to Storage Area Networks (SANs) is unique in its comprehensive coverage of SAN installation, cost justification and investments, and the latest standards. The book is a thorough, up-to-the-minute professional's guide to every aspect of SAN and disaster recovery, from planning through installation and management.

The high availability of mission-critical systems and communications is a major requirement for the viability of the modern organization. A SAN disaster could negate the capability of the organization to provide uninterrupted service to its internal and external customers.

Furthermore, the proliferation of powerful workstations and PCs, together with a vast installed base of minicomputers and mainframes, has produced immense pressure to link these resources. Local Area Networks allow the sharing of programs, data, and peripherals by providing common access to local and remote SAN resources.

This book provides you with the fundamental knowledge you need to design, configure, and implement SANs. The book emphasizes the integration of available software and hardware.

In this book, you also learn to identify vulnerabilities and implement appropriate countermeasures to prevent and mitigate failure risks. You learn techniques for creating a continuity plan and the methodology for building a SAN infrastructure that supports its effective implementation. Key features include, but are not limited to:

• Understanding basic SAN terminology, technology, and protocols
• Selecting SAN technology based on application requirements
• Configuring SANs to help interconnect the computing resources of your organization
• Supporting LAN storage
• Creating, documenting, and testing a successful SAN and disaster recovery plan for your organization
• Performing a risk analysis and Business Impact Assessment (BIA) to identify vulnerabilities in core processes
• Selecting and deploying an alternate SAN site for processing mission-critical applications
• Recovering SAN infrastructure, systems, networks, data, and user access
• Organizing and managing SAN and disaster recovery teams
• Testing and maintaining an effective recovery plan in a rapidly changing IT environment
• Performing threat and impact analysis
• Selecting alternative SAN and disaster recovery (DR) sites and equipment
• Planning your SAN and DR project
• Developing strategies for SAN systems and communications recovery
• Organizing team structures for use in an emergency
• Creating a SAN and disaster recovery plan from an existing template

The book is organized into seven parts and includes appendixes as well as an extensive glossary of SAN terms and acronyms at the back. It provides a step-by-step approach to everything you need to know about SANs as well as information about many topics relevant to the planning, design, and implementation of them. The book gives an in-depth overview of the latest structured SAN technology and emerging open standards. It discusses what background work needs to be done, such as developing a SAN technology plan, and shows how to develop SAN plans for organizations and educational institutions. More importantly, this book shows how to install a SAN system, along with the techniques used to test the system, as well as the certification of system performance. It covers many of the common pieces of SAN equipment used in the maintenance of the system, as well as the ongoing maintenance issues. The book concludes with a discussion about future planning, standards development, and the SAN industry.

Part I: Overview of SANs Technology

This part of the book coveres types of SAN operating systems software and hardware; the driving forces behind SAN; SAN market demand and projections; the evolution of the SAN market; and the value of information. Next, it discusses disaster recovery; I/O performance; high scalability and flexibility; technology platform, techniques, and alternatives; breaking tradition in video distribution; and SAP R/3 storage management. Part I also covers evolving standards for SANs and SANs standard organizations. Furthermore, this part discusses self-service SAN, outsourcing with service providers, high-speed data sharing among multiple computer platforms; Storage Area Networks: opportunity for the indirect channel, end-to-end services for multivendor enterprise Storage Area Networks and storage subsystems for video services. Finally, this part shows you how to reduce or eliminate single points of failure in enterprise environments—Storage Area Networks (SANs) can help improve the overall availability of business applications. High availability is achieved not through a single product, but rather through a comprehensive system design that includes all the components in the SAN. By utilizing highly available components and solutions (as well as a fault-tolerant design), enterprises can achieve the availability needed to support 24 X 7 uptime requirements.

Part II: Designing SANs

Part II begins by giving you an overview of how to design Storage Networks with Fibre Channel switches, switching hubs, and hubs; components; installation planning, and practices; application testing and SAN certification design issues; and SAN design documentation issues. This part covers the financial impact of a SAN, justification of SAN operating costs, and financial considerations and acquisitions. It also shows you how to design distributed SAN standards and discusses new standards design issues. Finally, Part II discusses traditional captive storage architecture, SAN architecture, and SAN design considerations.

Part III: Planning for SANs

Part III opens up by showing you how to make SANs a reality in your environment with your infrastructure; why Internet-based exchange pours resources into a SAN infrastructure; and how to prepare for a Storage Area Network. Next, Part III shows how SAN clustering technologies are an essential component of this new era of mission-critical web-based commerce. It also shows why sole reliance on industry-standard benchmarks for selecting the right hardware can be detrimental to the SAN architecture design. Finally, you'll learn how SAN simulation techniques can be used to understand the impact of your users, networks, and applications on the clustering requirements to ensure that your virtual doors are never closed.

Part IV: Installing and Deploying SANs

Part IV discusses physical layer testing, application layer testing, management layer testing, why you should use SAN Testing, and the SANmark Revision TestSuite. This part shows you how to deploy a SAN, get started on a SAN, use storage switch technology to accelerate the next phase of SAN deployment, and put data to work for e-businesses. Finally, this part covers SAN testing and troubleshooting; documenting and testing SANs; and certifying SAN performance.

Part V: Maintaining SANs

This part begins by taking a look at the data management solution, virtual Storage Area Networks, and a management strategy for the Fibre Channel-Arbitrated Loop. This part discusses the facts about SAN software; documentation standards; and increasing efficiency in the prepress market. Finally, this part covers present and future SAN management standards.

Part VI: SAN Solutions and Future Directions

Opening up with a discussion on the causes of data unavailability, cost tradeoffs, high availability objectives, and the SAN-including the single building, campus cluster, and metro cluster-this part examines solutions to making SAN work. This part also examines the role of SANs in computer forensics with regards to computer and data storage of evidence collection and forensic analysis. Finally, this part presents a summary, current conclusions, and recommendations for the future of SAN development and implementation.

Part VII: Appendices

Seven appendices provide direction to additional resources available for SANs. Appendix A is an online storage management checklist. Appendix B is a list of top SANs implementation and deployment companies. Appendix C contains SAN product offerings. Appendix D consists of standards for SANs. Appendix E is a discussion of SCSI versus Fibre Channel Storage. Appendix F is a list of miscellaneous SAN resources; and, Appendix G is a glossary of SAN terms and acronyms.

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