There are many reasons to implement a NAS or SAN solution in favor of DAS. If the requirements for storage consolidation, reduction in server count, centralized management of disk resources, SLA recoverability times, or near real time mirroring of data justify the cost of a SAN or NAS solution it is time to explore those options. To make an informed decision about when to make the switch it is important for you to pass through several phases:
Following this methodology will not only streamline the process of implementing new and more efficient storage technologies but also the process will provide valuable data to help upper management buy into the upgrades and support the storage program. Analyzing Your Storage NeedsThe first phase of any good project is an in-depth analysis of the environment and its needs. In the case of Storage Systems it is critical to identify any systems with special requirements. This would include systems that require multiple layers of redundancy, systems that are under extremely tight Service Level Agreements, and systems that cannot tolerate a loss of data. Another key area to understand is the capacity requirements of the enterprise. If an investment is going to be made in storage it is a good idea to plan for several years of growth. Look at the number of servers in the environment. If additional servers have been added simply because that is the way things were always done, it is time to look at shifting the philosophy to doing things because they are the right way to do them. Disk Drives Get Larger, Faster, and Cheaper Each Year Disk drives get larger, faster, and cheaper each year. When planning for the future, keep expandability in mind. By buying a partially filled chassis now and adding additional disks later, you can take advantage of falling disk prices and save money over the long run and still get the full capacity they need and the benefits of fewer chassis. Planning the Storage SolutionStorage technologies can be very confusing. In most situations, valid arguments can be made for using any of the available technologies. This is a situation in which it makes a lot of sense to get your vendors involved. Contact your potential vendors and let them know what your storage requirements are. Often times they have worked with other companies with similar needs and can provide valuable insight into what worked and what didn't. Given the costs of a large storage system, you can't afford to do it wrong. After you have an idea of what you'd like to implement, find out if there are reference accounts that you can contact to determine if they were happy with the solution they implemented. Some companies will try to get you to commit to the latest greatest versions of their software and firmware. Large storage environments are a big investment and business processes will depend heavily on it. Ensure that you are implementing a stable and well- tested solution. Does This Decision Support the Goals of the Project? There are a tremendous number of options when it comes to storage solutions. When in doubt about a decision, always refer back to the original goals of the project and ask yourself "Does this decision support the goals of the project?" Developing the Storage SolutionAfter you have determined the needs, explored the options, and come up with a plan, the real fun can begin. Any solution that will become part of the critical path of business must be developed and tested in a controlled lab environment. This is the part of the project where policies and procedures start to take form. Practice runs of mirroring, failing over of resources, and recovery of systems will ensure that the solution will be able to support the needs of the company. This development phase will identify several requirements that are not usually thought of during the planning phase. Most specifically these requirements are in the area of facilities. Most SAN devices are fairly large. An EMC Symetrix and Connectix, for example, will take up a full rack each. With heat generation more than 3,000BTUs, HVAC resources will need to be considered . Also keep in mind that most SAN and NAS solutions require 220V to run them. Ensure that planned data center locations have appropriate space, cooling, and power. Power should include not only the standard AC feed, but battery backup as well. Be aware of any special requirements of the SAN or NAS. Some SAN devices on the market will void their warranty if they are placed within five feet of any solid objects.
Piloting the Storage SolutionAfter the solution has been well tested in the lab, it's time to break it in limited production. Even extensive testing in a lab cannot always fully test all possible scenarios that a storage system will see in production. The best way to try to break the solution is to let users have access to it. Rolling the storage solution into a limited Pilot program will enable you to gather feedback about the performance of the system as well as feedback on the policies and procedures that will support the system. It's also a great time to get support staff trained on a system that they will likely end up supporting in full production.
Deploying the Storage SolutionAfter the system has gone through a final feedback loop from the pilot phase it is time to put the system into production. After following these steps you should have a well thought out solution that meets the current and future needs on the company. The solution will have been well tested and will encompass tweaks and improvements that came from the various testing phases. Performance metrics will be known and monitoring points determined. Now the company can begin to enjoy the benefits of the new storage solution. |