The Compaq Enterprise Network Storage Architecture: An Overview

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1 White Paper Doc. #12L8-0500A-WWEN Publication date: May 2000 Compaq Computer Corporation Executive Summary...3 Introduction...5 Compaq ENSA The Architecture...10 Compaq ENSA An Architecture for the 21 st Century...16 Conclusion...16 Glossary...18 Questions and Answers...19 The Compaq Enterprise Network Storage Architecture: An Overview Abstract: The Compaq Enterprise Network Storage Architecture (Compaq ENSA) describes a flexible approach to enterprise storage, in which servers can acquire storage though a unique utility gateway, as well as through traditional attachment methods. The Compaq ENSA vision, when fully realized, supports the creation of an Open SAN, an industry standards-based storage infrastructure that delivers the many-to-many functionality needed to meet the storage requirements of today s computing environments. Open SANs incorporate many of the elements of Compaq ENSA, including the creation of virtual pools of highly available, flexible, centrally managed storage. These pools consist of storage systems with added software functionality that can be widely deployed and managed symbiotically with computing systems and applications. Compaq Enterprise Network Storage Architecture provides reliable means to manage storage, including the ability to easily modify storage configurations, and to allocate storage dynamically and automatically on an as-needed basis to distributed application servers. The architecture also can quickly and easily restore and back up application data with minimal interruption of applications. In addition to its own management capabilities, the Compaq Enterprise Network Storage Architecture can be integrated readily with general enterprise computing management frameworks and tools. This white paper provides an overview of the Compaq Enterprise Network Storage Architecture and its underlying components.

2 Compaq s Enterprise Network Storage Architecture White Paper 2 Notice The information in this publication is subject to change without notice and is provided AS IS WITHOUT WARRANTY OF ANY KIND. THE ENTIRE RISK ARISING OUT OF THE USE OF THIS INFORMATION REMAINS WITH RECIPIENT. IN NO EVENT SHALL COMPAQ BE LIABLE FOR ANY DIRECT, CONSEQUENTIAL, INCIDENTAL, SPECIAL, PUNITIVE OR OTHER DAMAGES WHATSOEVER (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION OR LOSS OF BUSINESS INFORMATION), EVEN IF COMPAQ HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. The limited warranties for Compaq products are exclusively set forth in the documentation accompanying such products. Nothing herein should be construed as constituting a further or additional warranty. This publication does not constitute an endorsement of any non-compaq products mentioned. This test is not a determination or product quality or correctness, nor does it ensure compliance with any federal state or local requirements. Product names mentioned herein may be trademarks and/or registered trademarks of their respective companies. These include the following terms: Compaq Enterprise Network Storage Architecture, Storage Pool. Copyright 2000 Compaq Computer Corporation. All rights reserved. Printed in the U.S.A.

3 Compaq s Enterprise Network Storage Architecture White Paper 3 Executive Summary The Compaq Enterprise Network Storage Architecture (Compaq ENSA) addresses key business issues facing the Information Technology (IT) industry today: Knowledge is an important competitive advantage for any business. The drive to grow knowledge stores and improve storage hardware economics leads to explosive growth in storage and computing resources. As overall business success depends increasingly on software applications and their underlying data, continuous, reliable, and rapid access becomes critical and mandates guaranteed online access and quick restores of lost data. Storage management is becoming increasingly complex. Acquisition, retention, and efficient use of valuable IT professionals is critical. Rapid technology shifts offer competitive advantage opportunities for early adopters, but require both investment protection and non-disruptive, new product integration. The Compaq Enterprise Network Storage Architecture provides topologies, tools, and a roadmap to the future of storage. Compaq ENSA addresses these issues by transforming storage into a utility service that is accessed reliably and transparently by users, and is professionally managed with tools and technology behind the scenes. This is achieved by incorporating physical disks into a large consolidated pool, and then virtualizing application disks from the pool. Figure 1. The Compaq Enterprise Network Storage Architecture provides a highly flexible environment for data storage capacity and management. The Compaq Enterprise Network Storage Architecture is inclusive, and envisions an enterprise where storage area networks, network-attached storage, and direct-attached storage play important roles in meeting business requirements. Compaq ENSA offers significant benefits over other architectures. Many applications require storage with various performance characteristics, and Compaq ENSA provides appropriate

4 Compaq s Enterprise Network Storage Architecture White Paper 4 performance attributes to each application. While some architectures offer centralized storage, they may not provide a single repository that includes storage from other manufacturers like the storage pool that ENSA implements in the context of the Open SAN. Compaq ENSA offers the range of configuration, performance tuning, monitoring, and data protection capabilities needed to unify the enterprise storage environment. The Compaq ENSA concept of a storage pool allows a single storage repository that extends to any location in the world within a framework of open standards in the context of an Open SAN. This enables any-to-any connectivity between servers and storage. ENSA unites storage products with management tools and reporting capabilities that are developed in conjunction with the best solutions providers in the industry. The resulting unified, worldwide storage entity simplifies data management while allowing storage to be located near the applications it serves. The Compaq white paper titled: SANworks: Compaq Enterprise Storage Management Solutions provides specific details on how the Compaq ENSA vision is being transformed into a powerful reality that is leading to the creation of the Open SAN. BENEFITS The Compaq Enterprise Network Storage Architecture assists with: Managing Growth Compaq ENSA enables economies of scale to lower acquisition costs. Storage capacity is readily allocated to heterogeneous computer systems from a single common pool, as needed. The pool s capacity and other attributes can be easily expanded or changed. Leveraging Rapid Technology Change New products and technologies can quickly be incorporated into the storage infrastructure with minimal disruption. Compaq ENSA builds upon and leverages today s storage products, thus preserving investments in current storage and management technology. Data Management and Protection Compaq ENSA allows small teams to design, manage and grow the storage pool for the entire enterprise. Automated alternatives handle many of today s management activities. Virtualization the abstraction of physical storage is a key to making this work. Compaq ENSA logically consolidates physical disks into a large pool of capacity from which virtual disks are created for use by applications. Through the Open SAN, ENSA attacks the problem of data protection against all storage system failures. Compaq ENSA combines instantaneous data replication with tape backup and other capabilities to provide a complete, flexible spectrum of data protection and recovery capabilities. Instantaneous replication significantly reduces the cost of recovering damaged data while drastically reducing the time required to create protected copies of the data. Tape backup delivers long-term protection against most forms of data loss. Rapid restores, unobtrusive to applications, are also possible. Together, the tools offered by the Open SAN allow business to tailor their enterprise recovery to fit their needs. Ensuring Business Continuance Business Continuance requires that data be accessible whenever its host application needs it. Compaq ENSA supports continuous operation by providing prompt, reliable and

5 Compaq s Enterprise Network Storage Architecture White Paper 5 uninterrupted access to data. Also, the architecture allows for automatic, online data replication over unlimited distances worldwide. Balancing Security and Information Access Professional storage managers control access and ensure proper security and data protection. Providing Rapid Response to ever-changing user demands Resources are reallocated quickly, providing rapid support for new applications, changing performance requirements, and new servers. Performance Performance Geographically Distributed Data Management Resources Geographically Distributed Data Management Resources Traditionally, a difficult tradeoff Compaq ENSA mitigates the problem Figure 2. The Compaq Enterprise Network Storage Architecture provides the means to distribute data while preserving application performance and minimizing data management resource needs. Compaq ENSA is unique, because it provides the storage utility at all levels of cost, availability, and performance the application requires from inexpensive workgroup file and print to large servers, to highly available databases. Physical centralization of storage, or investments in large storage increments, is unnecessary. Instead, storage is delivered dynamically at the availability and performance levels required by applications. Compaq ENSA s commonality of components and software tools throughout the enterprise enables storage investments to be migrated among applications, availability levels, performance requirements, and other user needs. Total cost of ownership is minimized by logically centralizing configuration, management, and backup tasks for all storage rather than consolidating physical storage in a single data center. This translates into unprecedented levels of capacity and performance scalability, growth flexibility, with exceptionally high investment protection. Introduction Managing Storage in the Enterprise: The Problem Managing data, and the devices on which it is stored, has been accomplished on a server-byserver basis. Typically, storage capacity and infrastructure are purchased and added to individual systems. Alternatives exist. Compaq offers storage subsystems that allow consolidation of data from multiple heterogeneous servers within a single cabinet, and allow each cabinet to be managed as a storage entity. While this approach is useful today, a more complete model is needed to satisfy expanding business needs into future. Data protection is another major requirement. Today s RAID subsystems and hardware redundancy help protect against data loss from failures of individual disks, power supplies, or array controllers. Properly administered backup policies and attendant hardware and software

6 Compaq s Enterprise Network Storage Architecture White Paper 6 can protect against human error, software errors, and other loss. At much greater cost, redundant installations can protect against disasters. While these independent, interrelated techniques can work, they fail to meet today s business needs because they are expensive, intrusive, complex, and cumbersome to manage and maintain. A major problem today is the time it takes to restore data. This time is increasing with the volume of data and can be reduced only partially with substantial hardware and software expenditures. Compaq ENSA s instantaneous data replication provides the means to quickly and easily restore data, as well as reducing application downtime during backup.

7 Compaq s Enterprise Network Storage Architecture White Paper 7 The Compaq Enterprise Network Storage Architecture: A New Approach Unlike other approaches to network storage, such as Storage Area Networks and Network- Attached Storage, Compaq ENSA behaves organically while providing virtually unlimited capacity. The architecture supplies storage as a utility, similar to conventional electric and water utilities. Raw capacity is added as needed to a common pool, and prepared by storage virtualization engines for distribution to the application servers. It is then delivered, over a distribution fabric, to the application servers on demand. Distribution is both reliable and transparent to all applications served. Compaq ENSA incorporates storage devices, components interfacing to application servers, linking infrastructures, and common management tools that administer the entire environment. These elements communicate and cooperate to solve data storage and management problems. This organic behavior is totally transparent to all applications. Applications see only a reliable, available utility that conveniently delivers the storage they need on demand. Common Management Figure 3. Compaq ENSA provides a highly flexible environment Compaq ENSA leverages Compaq s highly regarded StorageWorks and SANworks capabilities: Storage devices, server technology, network architecture, infrastructure and other hardware components, all based on standards including SCSI and the emerging Fibre Channel standards. Intelligent networking expertise derived from clustered systems, SCSI clusters, and traditional general-purpose networking. Storage management software that delivers unprecedented power and flexibility in such areas as data replication, on-the-fly expansion and storage reallocation, disaster recovery, centralized management of distributed storage, and more. Experience developing a true storage utility that will make the concept of ubiquitously accessing virtual storage a reality.

8 Compaq s Enterprise Network Storage Architecture White Paper 8 A commitment to creating any-to-any connectivity with Open SANs, allowing the connectivity of heterogeneous systems with different operating systems to storage products from multiple vendors. Broad experience in testing and providing storage solutions for multi-vendor environments. Experience with diagnostics, serviceability, and system management. Extensive global services that provide consulting during design and implementation, assistance in planning for the future, and ongoing support. Partnerships with other best-in-class technology leaders to provide complete, integrated, tested solutions for a wide range of application and business needs. Compaq s Vision: Storage as a Utility Compaq ENSA s integrated architectural approach to allocating and managing data makes centralized, unified, policy-driven enterprise data management a reality. With Compaq ENSA, storage is a flexible, shared resource analogous to an electricity or telephone utility. Application servers access storage capacity simply, from a transparent pool through gateways that can be distributed throughout the environment. Customers Partner Services Figure 4: Storage becomes a utility which servers anywhere access as simply as plugging into a wall. The availability and reliability seen by all applications are independent of geographic location, server or application. These and other attributes are determined by policies that can be set centrally and maintained by the storage utility, like a central control room maintains switching and failover policies for an electric utility.

9 Compaq s Enterprise Network Storage Architecture White Paper 9 Similar to other utilities, Compaq ENSA s widely dispersed grids cooperate seamlessly to ensure customer satisfaction. The cost and life cycle of storage is separated from its system counterparts just as the electric grid s life cycle is detached from the appliances that access it.

10 Compaq s Enterprise Network Storage Architecture White Paper 10 Compaq ENSA The Architecture The Framework As computing environments become richer and more dispersed, storage solutions must follow suit. Compaq ENSA s philosophical approach is to distribute physical storage throughout the enterprise as needed, affording central management as appropriate. To satisfy ongoing computing needs, a network storage solution must incorporate several key attributes: Consistent, reliable access to data, regardless of the status of individual components anywhere in the storage system. Consistent, reliable and transparent access to data for heterogeneous operating systems. Performance required by applications whose data is stored on the system. Monitoring capabilities that provide useful reports of factors such as storage and performance utilization by applications. Unified, policy-driven, automated solutions to manage physical storage in increasingly distributed and complex environments. Compaq ENSA addresses these needs with storage virtualization, dynamic scalability, and powerful management tools, within a framework that offers maximum investment protection. Storage Virtualization Compaq ENSA creates a flexible, shared storage resource by applying storage virtualization on a new scale. Compaq ENSA allows vast amounts of physical capacity to be pooled across the enterprise for dependable presentation to application servers, wherever they may be.

11 Compaq s Enterprise Network Storage Architecture White Paper 11 Figure 5. Compaq ENSA s disks are created from the Storage Pool and provided to application servers. Compaq ENSA s virtualization technology allows disks of different capacities and data protection levels to be created from a set of physical disks. Virtualization occurs within the Storage Pool, which contains all storage assets the business chooses to deploy into the pool whether from Compaq or from other vendors and powerful virtualization engines. The Pool also grows over time. Initially it scales to satisfy the needs of a modest number of application servers. Over time, Compaq ENSA extends the Pool s span to a global scale with the addition of long-distance extension technologies. The Storage Pool comprises a single manageable entity from which storage capacity and performance are dependably delivered to applications. The latest interconnect technologies provide high-speed throughput and delivery of storage performance to the consuming servers. The Storage Pool works harmoniously with directattached and other forms of storage. Compaq ENSA disks the disks that applications access are created from the Pool. RAID and other techniques are applied to provide data protection. A Compaq ENSA disk can be accessed by more than one server, and a server can access many Compaq ENSA disks, within normal operating system compatibilities. Dynamic Scalability Unlike conventional disks, a Compaq ENSA disk s capacity is not limited by the physical disk capacity of devices in the Storage Pool. Instead, it is designated a capacity appropriate for the application. Compaq ENSA allocates physical storage capacity to individual applications automatically, based on the amount of virtual disk capacity actually used, until its designated logical capacity is reached. Compaq ENSA continuously monitors server capacity needs, and projects capacity from the storage pool. This means raw capacity provided to the pool can increase the physical capacity of a Compaq ENSA disk from the pool dynamically and transparently.

12 Compaq s Enterprise Network Storage Architecture White Paper 12 Figure 6. Storage pool capacity and can be expanded dynamically and unobtrusively over time. ENSA allows storage capacity to be redeployed among volumes within the Storage Pool. As one volume s needs decline, the excess capacity can be recovered and returned to the pool for reallocation to other virtual volumes. The distribution and connectivity facilitated by Compaq ENSA allows addition of virtually limitless capacity to the storage pool, in any increment at any time. This means vast Compaq ENSA disks can be created from significantly less physical storage than they will ultimately contain. Compaq ENSA System Managers merely need to be sure the pool has enough physical storage. Extraneous software management tools that reveal capacity allocation problems are no longer essential. Commitment to Standards-Based Computing Compaq has a clear and strong commitment to the development of standards for storage technology. In conjunction with the Storage Networking Industry Association (SNIA), we are working to establish the Storage Networking Technology Center in Colorado Springs, Colorado. The center will be a state-of-the-art facility for developing and testing open storage networking standards. Compaq Storage Products Division also plays an active role in all key storage industry standards committees and joint industry organizations, as well as a number of related consortia. For example, Compaq has long been an active member of the SCSI and Fibre Channel ANSI Standards Committee, was a founding member of the RAID Advisory Board, and participates in the SNIA Sponsored Storage Management Working Group for Fibre Channel (SNMWG-FC). The company also holds a seat on the Board of Directors of the Storage Networking Industry Association (SNIA), and is a strong contributor to and other industry organizations. Compaq s continuing involvement with these groups helps ensure that Compaq ENSA solutions provide the reliability and performance that computing environments require today and tomorrow within a standards-based framework that customers expect. Protection Against Data Damage and Loss Compaq ENSA combines several technologies to optimize data protection, as summarized in Figure 7.

13 Compaq s Enterprise Network Storage Architecture White Paper 13 Cause of Data Loss Hardware failure Software failure Human error Site catastrophe Today s Solution RAID, hardware redundancy Tape backup/restore Tape backup/restore Tape backup/restore Tape backup/restore Redundant online hardware at another site Compaq ENSA Solution Improved hardware redundancy Replication Tape backup/restore Replication Tape backup/restore Replication Tape backup/restore Site-redundant replication Tape backup/restore Storage Pool/SAN infrastructure Figure 7. Data protection mechanisms. Compaq ENSA uses RAID, redundant controllers and power supplies, network technologies, hotswappable components, and other mechanisms to protect against data loss resulting from hardware failures. Compaq ENSA also includes mechanisms to protect against data loss, software failure, human error, and site catastrophe. Data replication is the primary data protection mechanism. Replication creates identical copies of disks instantaneously and unobtrusively. Replicas can be used as sources for tape backup, providing archival protection from loss without disrupting any applications. Also, replicas can be used for application testing and other business purposes. Replication can be performed over distances to protect against site loss. In addition to quickly protecting data from loss, replicas can be sources for rapid and easy recovery from failures. The dramatic decrease in data recovery time significantly reduces downtime costs. Multiple replicas can be retained to satisfy application needs for point-in-time restores. Compaq ENSA includes tape backup capabilities, as well as replication. Tape backup complements replication by saving data to durable media either locally or remotely as well as archiving. Compaq ENSA s tape backup capabilities move today s backup methodologies into the domain of the Open SAN, thus freeing general enterprise networks, and eventually application servers, from the workload associated with backup. Simplified Management Compaq ENSA s automated management capabilities elevate the focus of storage management from the historic viewpoint of managing distributed individual volumes, physical devices and backup/restore and other policies to the higher perspective of the Storage Pool. Compaq s

14 Compaq s Enterprise Network Storage Architecture White Paper 14 Enterprise Network Storage Architecture offers the capability of creating central policies to control disks automatically, anywhere within the system. This functionality includes: Dynamic allocation of storage among disks with total application transparency. Redeployment of physical capacity among logical volumes. Flexible, reliable protection of data using replication, conventional backup, or a combination of the two techniques. Tuned performance within the Storage Pool. Storage usage monitoring for capacity planning, accounting, charge back, and other activities. Status monitoring and notification for key system attributes such as hardware, performance, and capacity utilization. Compaq ENSA simplifies remote system management by allowing disks for any application server to be created from any location. Compaq ENSA disks can also be reassigned to other servers and reconfigured from any location as needed. Compaq ENSA includes diagnostic capabilities that can be used by its embedded tools. Diagnostics are based on such industry standards like SNMP traps and MIBs, to allow use by Compaq s Web-Based Enterprise Management tool (WBEM; an emerging industry standard) and other external enterprise management frameworks. This feature allows Compaq ENSA to integrate easily into corporate enterprise environments. Compaq ENSA provides Application Programming Interfaces (APIs) that are being developed in partnership with leading software application vendors. These APIs allow third party application software installed on systems within the Storage Pool to execute their functionality, like backup and storage asset monitoring and accounting, through the Storage Pool. The APIs also facilitate communication between embedded management software and the applications that access Compaq ENSA disks, so application operations can be synchronized with replication and other management operations. Investment Protection Compaq has designed the Enterprise Network Storage Architecture to serve enterprise needs well into the future. Its farsighted approach allows Compaq ENSA to take advantage of new technologies as they become practical to deploy. In the StorageWorks tradition, Compaq ENSA evolution will be accomplished with maximum protection of existing Compaq Storage investments. While Compaq ENSA is revolutionary in its overall deployment, it provides evolutionary stages of technology deployment leading to the ultimate vision. Compaq ENSA allows environments to develop at their own pace from today s foundation. The evolution begins with today s Ultra SCSI components. It then grows through Storage Area Networks (Open SANs). The next stage expands to encompass conventional enterprise networks. Finally, the overall Compaq ENSA vision is realized as the enterprise storage networks are united within the worldwide Storage Pool. This allows for the planned implementation of the Compaq ENSA vision, with unprecedented levels of investment protection, even in the early stages of deployment.

15 Compaq s Enterprise Network Storage Architecture White Paper 15 Figure 8. Compaq ENSA Phases A key feature is that the new network storage environment is carefully designed to coexist harmoniously with existing direct-attach and network-attached storage. This means Compaq ENSA can be deployed incrementally as business needs change.

16 Compaq s Enterprise Network Storage Architecture White Paper 16 Compaq ENSA An Architecture for the 21 st Century The timing is perfect. Companies worldwide are seeking to transition into a 21 st Century business climate that s making unprecedented demands on their IT infrastructures in general, and their enterprise storage in particular. At the same time, Compaq is poised to offer a comprehensive, proven solution to 21 st Century storage challenges through Compaq ENSA. Compaq ENSA has evolved quickly from its initial concept stage only a few years a go into a proven solution today. For the customer, this means the ability to utilize top performing Compaq StorageWorks (disk subsystems, network components, links) and SANworks products (storage monitoring, management and other software) and technologies to create an impressive storage solution that delivers: High reliability and availability High speed from its storage through its interconnect capabilities Quick, easy recovery of data Real-time scalability of performance and capacity to meet user and applications demands Flexibility to make rapid, non-disruptive changes as the business evolves Powerful AND simplified management Availability of data across the enterprise And while the benefits currently available from Compaq ENSA are impressive, tomorrow s promise to be even more spectacular. Compaq ENSA will continue to evolve over the coming months and years to make the promise of delivering data to anyone, anytime, anywhere a reality. It will also continue to advance the technology of storage virtualization to make possible the management of data with unlimited capacity. The vision of Compaq ENSA, the impressive solutions that have already resulted from its implementation, and the advanced storage capabilities planned for the future clearly demonstrate that Compaq is best positioned to implement and deliver on the promise of network storage and the storage utility vision. Conclusion The world of enterprise computing is changing rapidly as businesses become more dependent on greater amounts of information and the knowledge derived from it for their continued success. This is driving explosive growth and complexity in storage as vendors strive to satisfy the demand for storage. Compaq has developed a unique approach to solving enterprise storage problems. Compaq ENSA is designed to evolve with the enterprise into the future. This unified vision encompasses not only storage hardware and software and the functionality that integrates it, but also extends to the services and support required to design, install, and maintain it. Compaq ENSA accomplishes this with unprecedented flexibility and protection of previous storage investments. Compaq ENSA incorporates the best of today s interconnects and

17 Compaq s Enterprise Network Storage Architecture White Paper 17 technology, and is designed to integrate new technologies well into the future, thus providing maximum application flexibility. Compaq realizes the entire vision by leveraging its acknowledged expertise in many technical areas, in partnership with the industry s leading solutions providers.

18 Compaq s Enterprise Network Storage Architecture White Paper 18 Glossary Compaq Enterprise Network Storage Architecture is the overarching term used to describe Compaq s flexible enterprise network utility concept, its customer benefits, the new way of thinking it brings about, its associated products, and other attributes from the server and business perspectives. Compaq ENSA disk is the name for the application-visible virtual volume presented to an accessing server. It has unique properties such as boundless expansion, availability and performance. Storage Pool is a collection of storage assets that is distributed over Fibre Channel SANs. Web-Based Enterprise Management (WBEM) is an emerging, standards-based management environment that unifies systems and network management and allows for easier integration and navigation between applications. Recently, the ability of WBEM to manage diverse storage arrays was clearly shown in a demonstration conducted by the Disk Resource Management (DRM) Working Group of the SNIA. Results of the demonstration are summarized in the January 2000 issue of Infostor (

19 Compaq s Enterprise Network Storage Architecture White Paper 19 Questions and Answers Q: What is a SAN? A: As defined in this paper, a Storage Area Network (SAN) consists of a collection of storage assets that is interconnected via a dedicated, high-speed, fibre channel network. The SAN is directly accessed by application servers, and uses storage protocols for communication among storage devices. Q: What is an Open SAN? A: An Open SAN is SAN technology at its best. It creates a true storage utility that makes the concept of ubiquitously accessing virtual storage a reality. This utility is designed to deliver two unprecedented capabilities: 1. Any-to-any connectivity, allowing the connectivity of heterogeneous systems with different operating systems to storage products from multiple vendors. 2. The ability to deliver data to anyone, anytime, anywhere. Q: How is Compaq s Enterprise Network Storage Architecture different from a SAN? A: The Enterprise Network Storage Architecture incorporates SAN technologies but goes beyond other SAN architectures in its intelligence, geographic distribution and management. ENSA s concept of a single storage pool greatly simplifies storage acquisition and management, because it allows storage devices to be physically near the applications they serve, while retaining the desirable attributes of centralized management. It also allows any logical volume to dynamically expand using physical storage from anywhere in the pool. Since virtual disks can be created for a number of file systems, pooling allows generic disks to be added to the pool, and for that capacity to then be available to a virtual disk for any supported platform. ENSA also encompasses NAS and Direct-Attached storage, integrating everything into a unified management environment. Q: Other companies talk about SANs being able to connect the storage from different sites together. This sounds like the Enterprise Network Storage Architecture. A: When other companies talk about SANs spanning different sites, they are really talking about linking a collection of localized, or site-wide, SANs into a larger network so they can be managed from a single location. These topologies have the latency attributes associated with the network technologies used. These SANs retain the basic properties of their component storage subsystems, and provide storage via a management response to application requests. Compaq ENSA provides storage automatically, and is not subject to the same network-induced performance characteristics. Also, the ENSA approach provides more flexibility to storage management and data protection than is provided in multi-site-spanning SANs. Q: What is driving the adoption of network storage products?

20 Compaq s Enterprise Network Storage Architecture White Paper 20 A: Network storage products offer benefits in such areas as backup, simplified management, and economies of scale. Also, putting storage on its own network can provide performance benefits to both applications and storage. Q: How is ENSA an open storage environment? A: ENSA is an open environment in many dimensions. ENSA is based on open standards like SCSI and Fibre Channel. ENSA incorporates components from many manufacturers. Also, ENSA uses storage systems from other vendors to create a true Open SAN. Q: What is a Storage Pool? A: A Storage Pool is an aggregation of physical storage capacity from which virtual disks are created for presentation to applications, plus the management tools to control and monitor the disks. Q: Does ENSA mean Compaq believes direct-attached storage will be replaced by storage networks? A: No. ENSA incorporates all attachment concepts including SAN, NAS, and direct-attached storage. Each has a specific purpose and will be supported moving forward. Compaq expects that customers will incorporate storage networks as their business needs require them, and direct attached and storage network-based storage will be intermingled based on the applications they serve. Q: Does ENSA mean Compaq believes a server-centric view of storage will be replaced by a storage utility? A: No. ENSA describes a flexible framework that accommodates both centralized and distributed computing models. Q: How does the Enterprise Network Storage Architecture fit into an overall Enterprise Management System? A: Compaq recognizes that the Enterprise Network Storage Architecture is a component of a larger computing environment. ENSA provides mechanisms, such as SMTP messages, which enable tight integration with larger enterprise network frameworks, such as Tivoli and CA Unicenter TNG. Q: Will Compaq ENSA support storage products from other vendors? A: The architecture is designed to be inclusive and open. ENSA will build upon and leverage products from many partners. Inasmuch as other vendors storage specific products adhere to applicable standards, it may be possible for them to integrate. Q: Which partners will Compaq engage for the Enterprise Network Storage Architecture?

21 Compaq s Enterprise Network Storage Architecture White Paper 21 A: Compaq has already engaged a number of hardware and software partners. Companies like Brocade, Gadzoox, Quantum and Seagate are contributing hardware technologies. Computer Associates, Legato, Seagate Software, Veritas and others are providing software technologies. Finally, Compaq is working closely with application and operating system vendors like Microsoft and Oracle to ensure that ENSA solutions work with key applications. Q: How will Compaq encourage ISVs to embrace ENSA? A: ENSA is broadly based on open standards and partnerships. Compaq is actively working with a number of industry standards groups and consortia to ensure ENSA s acceptance, and is working directly with a number of application and data management providers to create APIs that facilitate application integration into ENSA s management structure. Q: How do customers leverage the Compaq Enterprise Network Storage Architecture? A: The architecture provides customers a clear statement of direction from Compaq regarding the evolution and deployment of storage network technologies. Customers can now be assured that Compaq leads the industry with a complete vision that can be implemented based on open standards, partnerships, and excellence in execution. Q: How does Compaq's ENSA strategy relate to Compaq s NonStop ebusiness initiative? A: The Compaq Enterprise Network Storage Architecture provides the storage related components required for NonStop ebusiness applications. For more information, click here to view a white paper on this key topic: The Power of Compaq ENSA: Enabling Non-Stop ebusinsess Q: When can I expect to see Enterprise Network Storage Architecture-based solutions available for use? A: Solutions based on Compaq ENSA are available now. These make use of top performing Compaq StorageWorks (disk subsystems, network components, links) and SANworks products (storage management and other software) and technologies developed within the overall ENSA framework over the past few years. As development continues, customers will be able to integrate new functionality into the solution with assurances that their investment will be protected. Q: Why is Compaq uniquely positioned to deliver on the ENSA vision? A: Compaq is the only vendor that can provide fully integrated storage solutions forming a storage network from the workgroup to the data center. This commonality of components and software lowers total cost-of-ownership (TCO) and improves flexibility. Compaq is proven best in class at delivering solutions based on industry standards and partnerships again lowering TCO and ensuring best-of-breed performance and features. Compaq is the only vendor that can provide world-class service and support that cover not only the storage but also the servers and other parts of the customer s computing environment. This

22 Compaq s Enterprise Network Storage Architecture White Paper 22 means Compaq is a single point of contact for any problems arising anywhere in the environment.