Storage for the Network: Designing an Effective Strategy
In an information environment, an organization's success is tightly coupled to its ability to store and manage information. Storage systems provide a critical part of an organization's network infrastructure. With the amount of data growing at an incredible rate, your storage strategy must keep pace. In designing a storage strategy for your organization, you must select the right technology for your primary storage system, implement solid backup procedures and ensure ongoing management of the system. The Need for Storage A computer's main memory holds active programs, data and computational results. The computer's efficient operation depends on data held in memory being available in a few nanoseconds. A computer's main memory uses Dynamic RAM (DRAM): It stores data and provides almost instantaneous access to that data, but is limited in and is gone once the computer is turned off. Permanent storage holds the data and software that must be preserved even when the computer is powered down. Permanent storage needs can be immense. An organization's library of software applications can easily exceed many gigabytes, and the quantity of data can range in the terabytes. Financial systems, customer databases, electronic documents, bitmap images, digital sound and video are but some examples of the data on which organizations rely. A key part of the network infrastructure involves the hardware and software that stores the organization's ever-growing data. In designing a data storage strategy for an organization's network, the stakes are extremely high. The data stored on the network is a vital resource that cannot be re-created. Give care to provide adequate capacity, fast performance and reliable access, but at all means never allow data loss.
Storage Strategy Design Issues
As you construct a storage system, keep the following goals in mind:
Prevent data loss
Offer adequate capacity that can easy scale as storage needs grow
Provide fast access to data without interruptions
Be prepared for equipment failures
Use cost-effective technologies
Cost Analysis
A vital part of designing a storage system involves a careful cost analysis. Be sure to include all cost components. The major ones include:
Capital outlays for hardware: disk drives, controllers, enclosures, power supplies, jukeboxes, tape drives, CD-ROM drives, etc.
Media costs: tape cartridges, optical platters
Any required software: RAID utilities, backup software, HSM software, systems management utilities
Ongoing costs: hardware maintenance, software maintenance and upgrades, product/technical support
The development of the cost analysis may be an iterative process. Design a system with the highest performance and reliability possible with generous capacity in your initial analysis. If this package does not then fit within your budget allotment, then incorporate other lower-cost storage technologies for selected tiers of storage.
Risk Analysis
The security of your organization's data reigns supreme in the design of a storage system. It is important to assess the impact of the possible failure of your organization's storage system. Be sure to consider the following factors:
Productivity losses. Many, if not most, individuals in the organization will not be able to carry out their normal activities when key components of the technical environment--such as the network storage system--are inoperable.
Asset recovery costs. When data are lost, the organization must channel resources into its recreation. Recovering data from archives and backups requires effort of technical staff. The re-keying of irrecoverable data can be a massive undertaking. * Loss of active sales. Organizations that depend on their storage environment to support sales may not be able to process financial transactions during periods of failure.
Loss of customers. Prolonged or frequent failures diminish confidence in an organization by its clients. It is relatively cheap and easy to construct a storage system that works 98% of the time. Eliminating the last few points of downtime possibilities can double or triple the cost of a storage system. The investment you make toward enhancing reliability operates much like an insurance policy. The financial value of the organization's operation guides the expense that can be justified for reducing the likelihood of downtime and reducing the recovery time from failures. As you design a storage system, carefully measure the risk of failure for each alternative. Consider a wider range of alternatives. Start with a mental model of a system that initially seems to match your organization, and then work through design changes that both increase and decrease reliability. Finally, weigh the cost implications of the design alternatives against their relative risk factors and the impact of downtime to the organization. No magic formulas apply to risk analysis, but considering all these factors will lead to a solution w ell-matched to your organizations needs. By Marshall Breeding
