WHITE PAPER Extending the Benefits of Storage Area Networks across IP Networks Introduction The phenomenal growth of Internet business and data-intensive e-business applications over the past few years has created an increasing need for more data and storage to enable the collection, organization, mining, accessibility, and availability of information. Storage networking delivers highly available and scalable storage services while reducing the cost and complexity associated with managing storage resources. Storage Area Networks (SANs) have become the standard platform to enable storage to service the ever-growing needs of businesses. Companies deploying SANs want to extend the benefits of consolidated storage and management across the enterprise by providing IP access to SANs. Storage Area Networks By providing a high-speed fabric for interconnecting storage devices and servers, SANs enable businesses to: Scale storage resources independently of servers Enhance storage availability and data protection Simplify the pooling of storage for more efficient utilization Consolidate data across server and storage resources Centralize and simplify data management and administration Perform efficient, fast, and secure backup of data Today, SANs are based on Fibre Channel technology, an industry-standard protocol that is well known for its high reliability, high performance, and low latency¾all crucial requirements for interconnecting storage systems. These high-performance SANs are primarily located in corporate data centers where high-performance servers can be networked to large pools of storage. A typical heterogeneous SAN architecture consists of multiple servers running several different operating systems (Windows NT, Solaris, or UNIX), several different storage systems (EMC, Compaq, IBM, or HDS), and a tape backup system all interconnected via a Fibre Channel switching fabric. All contents are Copyright 2001 Page 1 of 6
Figure 1 SAN Fabric Interconnects Servers and Storage Devices Brocade SilkWorm SAN Infrastructure Brocade SilkWorm fabric switches provide the world s leading networking foundation for SANs. Using Brocade SilkWorm switches, customers can connect servers with storage devices through a SAN, creating a highly reliable and scalable environment for storage applications. Extending SANs Beyond the Data Center As SANs scale to support larger amounts of business-critical data, there is a need to protect and access the data over larger geographic areas. Access to reliable, continuous information is increasingly important for every business, and the benefits of storage networks are being extended beyond the data center into LAN, MAN, and WAN environments. The cost benefits of consolidating storage resources for efficient utilization and centralized management are well-known. The requirement now is to extend these efficiencies into other environments that use other protocols such as TCP/IP, ATM, and SONET. Today, the dominant protocol for data traffic is TCP/IP. The storage and networking industries are working together to drive open IP storage standards, such as SCSI over IP (iscsi) and FCIP (Fibre Channel over IP), and accelerate the internetworking of Fibre Channel-based SANs over Ethernet-based networks. IP Access to SANs By providing universal IP access to data center SANs, iscsi extends the accessibility of data and enhances the utilization and management efficiencies of pooled storage. iscsi is an emerging standard within the Internet Engineering Task Force (IETF) for transporting block data using the SCSI protocol over IP-based networks. Ratification of the iscsi protocol will be completed in the second half of 2001. Together with other industry leaders, Cisco Systems is driving the standardization of open protocols such as iscsi to enable block access to storage over a common IP infrastructure. Brocade and Cisco share a common view that iscsi is an important emerging technology that will enable hosts connected via IP-based networks to access storage within a SAN, providing pooled storage benefits to a larger number of servers. Cisco SN 5420 Storage Router In addition to leading the iscsi standards efforts, Cisco is deploying one of the first commercially-available iscsi products in the market. The Cisco SN 5420 Storage Router allows IP-connected hosts and servers to access a Fibre Channel SAN. All contents are Copyright 2001 Page 2 of 6
Figure 2 Cisco SN 5420 Storage Router Enables IP-attached Host Access to Fibre Channel SAN Brocade and Cisco have worked together to verify interoperability between the Cisco SN 5420 Storage Router and a Brocade-based SAN infrastructure. Applications for this technology include primary storage for LAN-based servers outside the data center and remote backup for branch office servers. Applications A variety of SAN applications, including database, transaction processing, e-mail servers, application servers, and file servers, serve data to clients on the LAN and to users on the intranet, extranet, and Internet. In the data center, these applications can take advantage of the high performance, high reliability, and low latency of a Fibre Channel network, and enable consolidated storage management within this environment. Extending Storage Consolidation Beyond the Data Center There is a growing requirement to extend the benefits associated with SANs, such as centralized storage and storage management beyond the data center. This will bring benefits such as better storage utilization, reduced storage management costs, and enhanced protection and availability of data. iscsi has the potential to provide secure, universal access to the data center SAN via standard IP-based networks. Within a corporation, in a single building, or within a campus environment, many workstations, PCs, and servers are already connected via Ethernet networks using TCP/IP as the communication protocol. With the addition of a Cisco SN 5420 Storage Router to the corporate SAN, the computers have direct access to storage resources within the SAN, providing primary storage or replicated storage for a remote server. This simplifies storage management for LAN-attached servers and utilizes the corporation s storage resources more efficiently because the SAN-based storage is highly reliable and centrally managed. The following figure shows a possible implementation for primary storage of LAN-based servers in a campus network. All contents are Copyright 2001 Page 3 of 6
Figure 3 Providing Universal IP Access to SAN for Primary or Secondary Storage In this example, departmental servers use the SAN as their primary or secondary storage resource. Critical data is written to and managed by the data center SAN over the campus network. This implementation ensures a highly reliable, highly available environment for the critical data generated on these servers. By incorporating the server data into the SAN architecture, the data and storage resources can be centrally managed, backed up, and protected under a common storage management infrastructure. Consolidated Backup and Restore over the IP Network Existing IP infrastructure in a campus environment, or even IP-based WAN connections, can be utilized for remote server backup and restore operations. The following factors drive the desire to consolidate backup and restore capabilities and to centrally manage the process: Tape backup systems and tape libraries are both resource-intensive and expensive. Data is becoming an extremely valuable asset to most businesses, and there is a growing need to protect those assets by storing multiple copies of the data in different locations. Because of the large quantities of data associated with backups, companies have typically performed the tape backups onsite and then physically transported the tapes offsite to provide disaster protection. When data needs to be restored, the restoration process can be error-prone, time-consuming, and expensive. The following figure shows how remote servers are backed up over campus-wide, MAN, or WAN connections, providing a cost-effective tape consolidation solution using Brocade and Cisco products. All contents are Copyright 2001 Page 4 of 6
Figure 4 Providing Centralized Backup for Local or Remote Systems Instead of transporting physical tapes to and from an offsite location for data backup and restoration, it can be significantly more efficient to back up and restore data from a network-connected, centralized tape facility. This also enables multiple servers and locations to share a single tape library. Remote backup is performed as an asynchronous application in which bandwidth, rather than latency, is the major consideration. To ensure that this high-bandwidth traffic does not interfere with time-critical traffic, it can be given an appropriately lower priority using the rich quality-of-service (QoS) capability available in the Cisco IP infrastructure. Summary By building an enterprise-wide storage networking infrastructure, companies lower their total cost of storage ownership and meet their business goals of creating a highly available, accessible, and manageable storage environment. A company-wide storage network infrastructure enables this by allowing companies to access and interconnect storage across campus-wide, metro-area, and wide-area networks. Towards this goal, dense wave-division multiplexing (DWDM) technology and open IP-based technologies, such as iscsi and FCIP, are being developed to extend SANs beyond the data center. The combination of the Brocade SAN infrastructure, Cisco Intelligent IP networks, optical DWDM solutions, and new iscsi storage networking products from Cisco, enables customers to extend storage access into LAN, MAN, and WAN environments and take advantage of the reliability and performance offered by their SANs. Together, Brocade and Cisco bring to the market world-class solutions for managing, accessing, and sharing storage resources. All contents are Copyright 2001 Page 5 of 6
Corporate Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA Tel: 408 526-4000 800 553-NETS (6387) Fax: 408 526-4100 European Headquarters Cisco Systems Europe 11, Rue Camille Desmoulins 92782 Issy Les Moulineaux Cedex 9 France Tel: 33 1 58 04 60 00 Fax: 33 1 58 04 61 00 Americas Headquarters Cisco Systems, Inc. 170 West Tasman Drive San Jose, CA 95134-1706 USA Tel: 408 526-7660 Fax: 408 527-0883 Asia Pacific Headquarters Cisco Systems Australia, Pty., Ltd Level 17, 99 Walker Street North Sydney NSW 2059 Australia Tel: +61 2 8448 7100 Fax: +61 2 9957 4350 Cisco Systems has more than 200 offices in the following countries and regions. Addresses, phone numbers, and fax numbers are listed on the Cisco.com Web site at /go/offices. Argentina Australia Austria Belgium Brazil Bulgaria Canada Chile China PRC Colombia Costa Rica Croatia Czech Republic Denmark Dubai, UAE Finland France Germany Greece Hong Kong SAR Hungary India Indonesia Ireland Israel Italy Japan Korea Luxembourg Malaysia Mexico The Netherlands New Zealand Norway Peru Philippines Poland Portugal Puerto Rico Romania Russia Saudi Arabia Scotland Singapore Slovakia Slovenia South Africa Spain Sweden Switzerland Taiwan Thailand Turkey Ukraine United Kingdom United States Venezuela Vietnam Zimbabwe All contents are Copyright 2001 Printed in the USA. Brocade SilkWorm and the Brocade logo are registered trademarks of Brocade Communications Systems, Inc. Cisco, Cisco IOS, Cisco Systems, and the Cisco Systems logo are registered trademarks of Cisco Systems, Inc. or its affiliates in the U.S. and certain other countries. All other brands, names, or trademarks mentioned in this document or Web site are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco, Brocade and any other company. (0102R) SPS 4/2001