With the advent of cutting edge technologies for storage of information, organizations can choose from a plethora of data storage options. SAN and NAS are the most sought after formats of storage system for allowing fast and easy access to data. One must not forget role of cloud and object storage systems as these are found to significantly impact enterprise storage strategies.

Difference Between NAS And SAN Storage

In essence, rather than leveraging a file system application, Network Attached Storage (NAS) allows a format for serving files.  It uses a remote protocol to redirect file access to another device that is designed to perform as a server that has its separate file system. Such a device not only operates as a centralized resource for management of data but also enables file sharing and handles file input and output.

In order to facilitate several different servers to access storage without any hassles, a Storage Area Network (SAN) leverages a switch and is attached to a fabric. In terms of Operating System or server application, one cannot easily differentiate between accessing a directly connected storage and in a Storage Area Network. The data is managed by allowing its block access by SAN storage format that is similar to DAS (Direct Attached Storage).

Elements of Storage Area Network

SAN integrates a large array of storage devices, switches, and hosts that are interconnected. The connection between these components can be established by leveraging different protocols including the legacy option of fiber channel, which continues to be most sought after alternative.

As an effective alternative to Fiber Channel, you can also use FCoE that leverages power of available Ethernet to facilitate traffic across Fiber Channels. Fiber Channel over Ethernet also helps congregate Internet Protocols and storage within a unified infrastructure.

One can also choose from other options, depending upon the organizational objectives that include InfiniBand if there is a need to support high performance computing. Alternatively, Internet Small Computing System Interface can be used if you are running a small or medium infrastructure.

Use cases

A decision to use either SAN or NAS depends upon the type of I/O. Since Network Attached Storage converts request for input or output into block access to help storage of data in the attached device. This also implies use of Network Attached Storage(NAS) to handle file input and output workloads. On the other hand, Storage Area Network is ideal for block I/O.

If you are required to deal with data workloads including communications, social media, video files, and any type of file having unstructured data, the most preferred choice would be NAS even though it is usually leveraged for handling structured data. So whether you are concerned with relational database having structured data or unstructured data, NAS can be a perfect solution.

The differentiation between NAS supported file storage and block storage related NAS format slowly becoming irrelevant as prevalence of object storage is growing. The principal reason for this shift is adoption of cloud computing by more and more enterprises.  

Users are always inclined to ensure data access in the traditional manner because there is a certain level of comfort in old habit of using NAS to support file storage and SAN for achieving block storage. This has prompted cloud vendors to build back end with object storage and a SAN or NAS for front end of systems.

Review Of Available Storage Systems

Users can choose from three major storage options including block storage, object storage and file storage. It would be beneficial to understand these in terms of their features. Data is written in the same fashion as hard drives of personal computers in file I/O that maintains data be making use of a hierarchical structure by making several folders within folders.

While a similar approach is used by NAS system, one can derive an array of benefits too. These systems enable IT departments of the enterprise to manage storage without any hassles. Copying and pasting of complete folders as possible if the commonest SMB and NFS protocols are used for implementation of NAS systems.

In order to achieve higher data reliability and faster data accessibility, block I/O storage approach can be used. Such an approach distributes several copies of every block where folders and files are treated as blocks.

On the other hand, object I/O storage is more of a singular type since every file is treated as a single object. In this approach entire gamut of objects which are nothing but files are stored in a unified pool of database that has a flat structure. Files are located by viewing metadata.

Place for DAS

A storage system that is not part of the network system and has a physical existence similar to a dedicated server is referred to as DAS. In such system one must physically establish connection with the storage just like a hard drive that is commonly used to store and retrieve data.
Although these storage options can deliver superior output in dealing with compute intensive software applications, one needs to deal with many complexities. It cannot allow sharing of storage among several remotely located users and is devoid of cutting edge features of storage management including thin provisioning, data replication, and so forth.

Way Forward

We are entering in an era of unified storage where storage administrators will enjoy supreme flexibility using the same array for running storage or blocks. Enterprises can leverage a single platform for consolidating NAS file intensive data with SAN block intensive data. Unified storage systems are designed to eliminate reliance on hardware by greater adoption of virtualized storage as well as cloud storage.