SAN vs. NAS
Why are we still having the SAN/NAS debate when they both fit into total storage network solutions?
First of all, there is no debate. Both SAN (storage area network) and NAS (network attached storage) solutions have a place in an organization's storage management strategy. You don't need a 500-page guide or a SAN/NAS For Dummies book to figure it out. What you need is a clear, simple understanding of a business' need and its pain threshold as it relates to storage growth and management.
Many "experts" begin the SAN/NAS discussion with the same "business data is exploding" argument, but unfortunately, someone forgot to tell the purchasing folks because overall storage purchasing is not really doubling every year. On the whole, storage growth will be about 6% to 10% year after year. However, SAN growth is roughly 77% and NAS growth is roughly 75%. So, growth is in storage management, which includes hardware, software, and services. Add that up, and you have a possible solution to a business problem.
Beyond Buzzwords To Business Solutions
Do you remember the movie Raiders of the Lost Ark? There is a scene in the beginning of the movie where Indiana Jones escapes several obstacles and is almost out of the cave. He just gets past the wall of spikes and his unscrupulous guide, and is ready to breathe a sigh of relief when this huge boulder starts rolling down after him. Our hero is about to be smashed, except it's the beginning of the movie and too soon for it to be over - much like IT challenges facing businesses today.
We, the IT folks, have to assume that the other executives in our companies are not in meetings talking about SANs, NAS, DAS (direct attached storage), or any other buzzword we experts come up with. Sure, these words are great for us folks, but for any executive running a business, the real questions are about business issues and how to become more efficient and more competitive. They want to see more of the net-net - What should I do? What is best for my situation? To answer these questions, let's take a look at the options.
The Virtues Of SAN, NAS, And VSN
SANs build on the server-attached model through the creation of a network of storage devices. This allows data to move more efficiently without adding more load to the communication network. Leveraging Fibre Channel connectivity, SANs provide a more robust performance for storage management. SANs allow servers to be physically separate from their storage devices with distances from 10 km to 100 km. This is far greater than the previous connectivity of a few feet.
The SAN approach is similar to LAN architectures in concept. These devices allow connectivity to many devices via hubs and switches and even directors for high availability. The Holy Grail of SANs is typically thought to be the virtualization of storage for a number of disparate applications, reducing hard dollar costs. Yet, most real business benefit comes from improved backup and data recovery.
NAS embodies many characteristics of a classic file server with many software and hardware features stripped out so the device focuses only on storage. Benefits of NAS include simple installation, lower cost per GB, and reduced management. NAS devices are a good fit on the low end or department level.
In the real world of storage networking, a much broader view of storage management is required. Enterprise users now consider the VSN (virtual storage network) as a total solution that can encompass both SAN and NAS.
SAN/NAS: Part Of A Total Solution
So, the decisive questions in the SAN/NAS debate are: How does an IT organization turn data into information that allows executives to make more informed business decisions? How does an organization maintain current levels of data for protection against possible disaster? The answer is the Virtual Storage Network that includes both SAN and NAS in most cases, and remote data access via VSN in all cases.
As with any IT business decision, the real question is, What is the return on an organization's investment? That takes the whole question of "Is it SAN/NAS?" out of the equation. Vendors want to influence or freeze an executive's decisions because vendors want business now. They couch all their products in terms of a solution, which in most cases gets lost in the translation. I know, because that is how I used to sell storage.
Today, both the reseller and direct sales models have places in selling storage to global organizations. The SAN/NAS question makes the argument that one or the other is a fit, when in actuality, both technologies fit squarely into a large data center or enterprise.