Business is fueled by information. The success of a business is determined by the architecture, speed and reliability of access to enterprise information. Logically, enterprises place themselves in a more strategic and competitive position with well-defined information architectures, highly available network technology, and the capacity to access information quickly. Nevertheless, because the amount of information an enterprise must retain is growing at an astounding rate, it is becoming increasingly difficult for enterprises to effectively manage critical information and quickly locate needed data,
What this all means is that information does not stop once its base starts growing -- information continues to build on information. The challenges resulting from exponential information growth that enterprises must overcome, and the importance of selecting and managing a storage solution that works to this end-to-end, are critical issues that must be successfully navigated by a company in order for it to maintain its competitive edge. Several factors contribute significantly to the explosion of information that challenges an enterprise's success.
The occurrence of mergers and acquisitions is the first of these factors. As companies come together, the quantity of data multiplies and becomes distributed across the enterprise. This distribution not only makes information management increasingly complex; it also makes locating information increasingly difficult.
Second, the expanding use of the Internet and e-commerce applications only serves to perpetuate the information management problem. The majority of an enterprise's storage resources can be consumed by the large amount of data and cumbersome text, audio, image, and video files used in Internet and e-commerce applications.
Third, as the number of users and the quantity of data increases, so does the demand to share resources across the enterprise. Existing information management challenges are intensified by the existence of proprietary technology and the inability to share information.
Finally, additional stress is placed on computing resources as enterprises continue to broaden their customer bases. The delivery of fast, reliable access to enterprise resources is made difficult by this stress.
The culmination of these factors leaves enterprises with a plethora of unorganized information and strained technology resources. Inevitably, user productivity slows and computing systems go down. Also, as enterprises attempt to make sense out of chaotic information architectures, they scramble for a solution that offers past and future technology investment protection, lowers total cost of ownership (TCO), and enables quick, reliable information access across the enterprise. Nevertheless, more and more enterprises realize that the storage capacity and performance necessary to meet these needs by general-purpose servers is lacking.
Storage Solution Selection
Imperative to the future growth and success of an enterprise is the choosing of a dynamic and adaptable storage solution. Several important issues must be considered as enterprises move toward implementing a storage solution:
The ease of use and reliability of a storage system are tremendously important because once data is lost, it cannot be recovered.
- The optimal storage strategy not only provides storage but also allows enterprises to invest in a total network solution.
- The storage solution selected must meet the current needs of the enterprise and, at the same time, allow for growth and expansion.
Network Attached Storage
NAS servers attach directly to enterprise Local Area Networks (LANs) and are designed specifically for storage and file/application services. The ability to provide high performance storage, speedy file access, and interoperability in one, simple solution lies in the advantage and innovation of NAS. The high storage capacity and cross-platform capabilities of NAS result in the consolidation of existing network resources into a single system with a streamlined architecture. As a result, users are granted rapid, reliable access to shared data, while the enterprise enjoys increased storage capacity and lowered TCO.
The NAS unit appears as a very large hard drive to users. By using network protocols such as Transmission Control Protocol/Internet Protocol (TCP/IP) or file sharing protocols such as Common Internet File System (CIFS), Network File System (NFS), and Hyper Text Transfer Protocol (HTTP), users are able to access files and applications directly from file systems residing on the NAS device. Furthermore, performance problems and input/output (I/O) bottlenecks caused by the transmission of requests across multiple servers are eliminated, because users submit file and application requests directly to the server. Data requests, as a result, are handled faster and more reliably by a NAS system than by general-purpose servers.
Currently, NAS appliances are most often deployed in environments that require high overall performance for web and e-mail services, data warehousing, Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) development, graphic design and imaging, and rapid access to information libraries and archives. Nevertheless, NAS is ideal for both large enterprises with large information bases and small companies looking to expand in the near future.
For example, the International Data Center (IDC) reports that from 2000 to 2001 NAS revenue grew from $1.3 billion to $5.6 billion, an increase of 331%. IDC predicts NAS consumer spending will reach $21.1 billion by the end of 2005, with a compound annual growth rate of 69%. The demand for, growth of, and increased spending on NAS is larger than that of any other storage technology. Because of its ease of installation, catastrophe-free performance, and key features, NAS has now become the storage standard. For system installation and configuration, other storage solutions demand hours -- and sometimes even days -- of network downtime. Because network downtime is minimal, the plug-and-play capabilities of NAS servers make deployment in any environment simple. In comparison to other storage solutions, the architecture of NAS servers provides increased performance, manageability, availability, scalability, and reliability in addition to its ease of deployment.
Server Attached Storage
Server Attached Storage, also referred to as Direct Attached Storage (DAS), entails the attachment of storage disk arrays directly to general-purpose servers. Under this architecture, users submit I/O requests directly to the disk controller residing on the server to which a user is connected.
With minimal storage needs, server-attached storage is typically more effective for smaller enterprises. However, for rapidly growing and large enterprises, the architecture of server-attached storage environments may be problematic. Server-attached storage often exacerbates IT problems, though the addition of storage to existing servers in the network may seem logical. As enterprises continue to invest in server attached storage, information becomes increasingly distributed across the enterprise and isolated from users not directly attached to the storage device. Thus, the installation and maintenance requirements of server-attached storage compound these problems.
Though DAS offers a simple way to add needed storage, administrators must continually add storage arrays and work to maintain a complex, distributed network. This often causes more problems than they are solving. As a result, enterprises run the risk of heightened TCO due to increased IT expenditures in administration, overhead, and decreased user productivity.
Server Attached Storage versus NAS
NAS also offers enterprises several other advantages over server-attached storage. NAS not only provides network simplification but ample storage capacity as well. As previously mentioned, the installation and maintenance of server-attached storage solutions can be time consuming and require network downtime. Alternatively, NAS only requires a few minutes of downtime during maintenance and upgrade, and users retain the ability to access file services on the appliance. NAS solutions offer large enterprises the capacity they need in one device and small enterprises the room to grow.
Furthermore, with a NAS solution, enterprise information resources can be consolidated onto one system. In addition, by streamlining network architecture with NAS, storage and file resources are shared by the entire enterprise, and administrators need only be concerned with maintaining one system. Among other advantages, this results in simplified system backups. Why? Because with NAS, only one server must be backed up, rather than multiple, dispersed server-attached storage arrays. In short, with a NAS solution, enterprises effectively increase user productivity and lower TCO.
The Server Attached Storage strategy causes enterprise resources to become more distributed and network maintenance more difficult. Users in a server-attached storage environment experience sluggish performance, suffer from unavoidable system downtime, and are typically incapable of sharing files across operating systems. As an alternative, NAS supplies enterprises with:
- Centralization of resources and management,
- Enhanced performance,
- Increased system uptime,
- Necessary storage capacity, and
- The ability to share files transparently across the enterprise.
Storage Area Networks (SANs)
A SAN involves a complex web of servers and storage devices which are linked via an I/O connection, such as Fibre Channel. As storage capabilities are becoming enormous and I/O is handled rapidly, the performance, availability, and reliability of SANs cannot be disputed. The speed of Fibre Channel and the capacity of SAN Systems supply enterprises with fast access to an abundance of stored information.
By deploying a SAN solution, an architecture is also created in which storage devices are separate from file and application servers directly accessed by users. Also, network traffic and congestion is reduced by the isolation of the storage array from the network. In addition, because SAN arrays are connected via Fibre Channel, the bandwidth for storage requests by clients is increased. However, a period of delay in file serving is created, since all I/O requests submitted to the application servers for file access must pass over the SAN array.
SANs versus NAS
SANs are most appropriate for providing immense storage capacity to very large enterprises. SANs also offer minimal network interference. Furthermore, given the capacity and speed of SAN systems, one naturally questions how NAS could possibly offer any advantages over SANs. NAS systems offer comparable performance and provide enterprises of all sizes more than enough storage capacity for current and future needs, so neither solution enjoys an edge in these two areas. However, because SANs require significantly more IT planning and network downtime for installation, the advantage of NAS over SANs is evident in the ease of installation and maintenance. Additionally, NAS offers cross-operating system file sharing and storage pooling. Because these features aren't currently available in SANs, SAN implementation (as opposed to NAS implementation) restricts future business investments in technology and enterprisewide file sharing,
Summary and Conclusions
In terms of network management, information is growing faster than ever predicted, posing considerable challenges to enterprises. Several storage solutions are available to help enterprises overcome the multitude of challenges associated with information growth. These solutions can be grouped into three distinct categories: Server Attached Storage, Storage Area Networks (SANs), and Network Attached Storage (NAS). Among these solutions, NAS enjoys several advantages in that it is easier to install and maintain, provides superior performance, and offers ample storage capacity.
John Vacca is an information technology consultant and internationally known author based in Pomeroy, Ohio. Since 1982, John has authored 39 books and more than 485 articles in the areas of advanced storage, computer security and aerospace technology. John was also a configuration management specialist, computer specialist, and the computer security official for NASA's space station program (Freedom) and the International Space Station Program, from 1988 until his early retirement from NASA in 1995. John was also one of the security consultants for the MGM movie titled : "AntiTrust," which was released on January 12, 2001. John can be reached on the Internet at email@example.com.