CD-ROM technology is exploding. According to Dataquest, nearly 25 million CD-ROM drives were shipped in 1995.
This number is expected to expand to 50 million units by the end of 1998, and upwards of 70 million by the year 2000. CD-ROM is now the most popular media used to distribute software. Due to its capacity, (a standard CD-ROM disc can hold up to 650MB of information, or the equivalent of 130K pages of text), durability, low production cost and ease of packaging and distribution virtually all new software titles are produced using CD-ROM.
As more and more software applications are distributed and deployed on CD-ROM, companies are beginning to look at ways to share this information resource within corporate network environments. The adoption of the ISO-9660 CD-ROM format standard, supported by nearly all of the popular computing platforms allows CD-ROM data to be read by users of DOS, Mac, Windows, UNIX and OS/2 systems. Since most of these environments reside in today's corporate, government and educational institutions it is a natural evolution for users to maximize and share CD-ROM information across platforms.
Why Network CD-ROMs
It's a relatively simple question of economics and sound business practice. Organizations that make valuable CD-ROM based information available empower their employees to instantly access time critical information, make decisions quicker, and easily access to a myriad of new CD-ROM information.
Shared CD-ROM resources enable departments and workgroups to eliminate redundant efforts between groups to reduce the cost of CD-ROM subscriptions. With a shared CD-ROM resource on the network, organizations can also provide better support and responsiveness to its customers while promoting better communication within its own organization.
Most large organizations use several types of computing platforms, including PCs grouped together using NetWare, various UNIX dialects supporting TCP/IP, and most likely several application servers running Windows NT. Today's CD-ROM Server solutions allow all of these environments to share the same CD-ROM subsystem and information simultaneously. There are several types of solutions available, from file server-based software solutions to file server independent products that sit out on an ethernet or token ring as an intelligent node.
CD-ROM Subsystems as a Network Appliance
A networked CD-ROM subsystem incorporates three distinct technologies:CD-ROM drive devices, network connectivity technology and data storage management products. Below is a quick analysis of each technology, and where they fit.
Developments in CD-ROM - New developments in this technology will soon offer storage capacity of up to two full-length feature films, or 18 GB (gigabytes). Because of its capacity, software manufacturers consider CD-ROM the most attractive media for distributing their software. What normally would require dozens of 3 1/4” floppies now only needs one CD-ROM.
Developments in Network Connectivity - Mobile computing, multimedia applications, web browsing, all have placed considerable stress on first generation networks. With improvements ranging from the volume of data that can be managed to more efficient management of bandwidth demands generated by these developments, network operating systems have evolved to a point where they can absorb and support the many advancements anticipated in next generation computing.
Developments in Data Storage Management - CD-ROM networking technology incorporates the early rudiments of the new concepts of network data storage management. Similar in concept to virtual memory, network data storage management is a process whereby the network will store data independent of user or network server interaction. Networks of the future will judge and make the constant trade-off decisions between the cost of the data storage medium employed and the predicted speed requirements of its retrieval.This concept vastly differs from today's systems where it is the network administrator's responsibility to determine the storage medium for each piece of data to be saved.
Like today's virtual memory utilities, the advanced network data storage systems of the future will be transparent to the user and will work under the premise that the greater the distance both physically and logically from the network the data is stored, the least costly the storage will be. Network CD-ROM Servers attached to towers and jukeboxes will be the enabling technology central to this new concept of network data storage management. A CD-ROM subsystem filled with terabytes of blank media will become the near-line data warehouse of the network of the future. Under only the network's control, these masses of cheap available storage space will be constantly and virtually consumed with all data the network has ever processed.
The rate at which CD-ROM technology is assimilated into an organization is wholly dependent upon those CD-ROM applications utilized or about to be utilized by them. Because of the appeal of the medium, the number of CD-ROMs being made available to each professional, business, and technical discipline is growing at an exponential rate. From engineering to law, from medicine to industrial safety standards, paper is being abandoned in favor of CD-ROM as the preferred publishing medium. In addition to these “off the shelf” databases, many organizations are developing and publishing their own CD-ROM applications.These applications range from internal procedures and policy manuals to archival of in-house data and computer output to laser disc (COLD storage).
Although the first requirements in an organization for CD-ROM connectivity generally occur on the workgroup level, departmental and enterprise level implementations can also quickly become priorities. Consequently, as the technology moves further out in to the corporate void more and more protocols and NOSs need to be supported as more and more environments come on-line.
Multiple Approaches to Networking CD-ROM
Networking CD-ROM drives offers significant benefits. There are several different methods available to achieve basically the same result. Some are hardware oriented, while others employ a software approach. Some use existing file server resources while others are file server independent. These solutions fall into four categories based on their architectural approach: using an existing file server, redirecting information requests from the file server to a CD-ROM server, accessing another peer's CD-ROM drive, and utilizing an independent CD-ROM server. The CD-ROM networking approach that will work best depends on the requirements of the specific network environment and the types of CD-ROM applications.
Factors to consider when choosing a CD-ROM networking architecture follow:
- Cost - Price is always an important factor in a purchase of network equipment. The cost of hardware, software, and license fees or per-user fees should be considered.
- Ease of Installation - The ease with which a system can be installed is of paramount consideration in today's networking environment. Solutions requiring access to the file server or a network shutdown are often not desirable. Installation will ideally be plug-and-play.
- Ease of operation - The amount of education required to get users up and running should be minimal. Ideally, they will be presented with nothing new to learn.
- Multiprotocol Support - The product should be capable of simultaneously supporting the major protocols used within the environment. Some solutions offer support for only one protocol at a time, or in a worst case scenario require you to purchase separate products!
- Impact on File Server - Solutions that use file server resources can cause performance or throughput problems, as file servers become burdened with the load of handling additional overhead. In addition, solutions that require a file server to be taken off-line and shut down during CD-ROM server installation are undesirable and impractical.
- Drive Location- In certain cases, such as major libraries, centralized drive location and management is preferred. In other cases, it is desirable to have the drives located departmentally.
- Performance and Throughput - Performance should be sufficient to meet the current and anticipated needs of the application. To ensure that performance is consistent, it should be independent of other activity on the network or file server.
- Doubling up on Network Traffic - Incremental network traffic should be minimized, particularly traffic over WANs or through multiple LAN segments connected to bridges and routers. Double traffic, whereby CD-ROM requests first hit the CD-ROM server, go back to the file server, hit the CD-ROM server again, to accomplish a task should be avoided.