Why NAS "and" SAN Storage           Why not print this out

Lets look at the Business Case

Think about media serving, where potentially thousands of copies of the same movie or video clip are being delivered to an equal number of users at the same time, but not necessarily at the same point in the clip. It will take many servers to deliver this same clip over and over again, in most cases pointing to a single file. So if you are serving up a large collection of web pages, or video streams, to many users at the same time across a variety of client environments, then network-based file access is required.

This can be done via storage attached to a general-purpose server, say Windows NT, or by putting storage directly on the network. Let’s be clear here. Disks are never directly plugged into the network. There is always a server of some sort managing that storage that appears to sit on the network. These servers range from general purpose (as with NT mentioned above), to configurable special-purpose file servers, to manufactured file-serving appliances.

Sometimes they are physically separate from the array of disks, other times they are collocated in the same enclosure.  The question to ask is "where does the sharing occur?" If it is at the file level, this is the primary reason for NAS - many, sometimes large, files need to be shared, typically by diverse servers. Examples of files that need to be shared can be found everywhere – network drives in an NT environment, workgroup CAD files, and web pages shared by many web servers.

Today, the fastest, easiest way to meet increasing web pages and web servers’ performance and capacity requirements is to use NAS. Benefits include scalability (no need to clone data to individual servers, just plug a new server into the network and you have instant access to consistent data) and manageability (fewer copies of data reduces storage staffing needs).

Some NAS storage solutions have point-in- time copy capability to allow for scaling the number of copies of data to be accessed allowing systems to be run in parallel. You can also use NAS to consolidate servers. In many environments, one highly available and scalable NAS solution can replace twenty general-purpose servers that have been dedicated to network file serving. This makes it easier to ensure that these business critical applications are available all of the time.

• Full testing, integration and support of SAN and NAS applications within a common storage infrastructure. This infrastructure should be capable of including both centralised and distributed information;

• The ability to add storage without interruption to on-line information processing regardless of application type, and the ability to redeploy those same assets to either architecture in the future as computing requirements potentially change; and

A single administrative interface to manage the combined, extensible, mixed-type storage infrastructure.

The battle is as much about the way to achieve scalability, as it is about connectivity. Over this decade, larger enterprises have to worry about scaling to hundreds, if not thousands, of terabytes. Most require both SAN and NAS in their infrastructure. The question is how to best do both.

Storage management software may mitigate this, but there is no getting around the fact that it is harder to manage many devices rather than fewer. In addition, the ongoing world-wide challenge of finding and retaining staff increases this complexity exponentially.

For now, few large organisations will be able to rely solely on enterprise storage servers. They will deploy SAN and NAS storage where they need it, mostly centralised in location, but not always, but hopefully all of it centrally managed.

The specific application requirements for shared file access or record-level performance will not change. Instead, storage vendors are moving toward unified solutions, which bring both SAN and NAS access to the same very-large array. It would accept multiple types of connectivity: IP for NAS and Fibre Channel for SAN, at least.

The array will be self-optimising, with a single management interface. We believe that a bigger unified storage server is better !

Be wary of the piece-meal approach to storage procurement. This will only bring more difficulties down the road.

The recommendation is you find the most manageable, effective, and unified storage solution to satisfy your enterprise’s diverse application requirements, in that priority order.

Push your storage suppliers to address all three and base your procurement decisions on their experience, references, and the coherency of their answers and plans.

It is no surprise that EMC offerings are at the heart of this revolution.

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