Making NAS your essential server

With benefits like better reliability, enhanced scalability and an easier installation process coupled with a 32 percent growth rate per annum, Network Attached Storage (NAS) is becoming the preferred storage solution across organisations, says Hari Padmanabhan

The modern enterprise is a mixture of platforms and computer systems of various capabilities with a range of specific functions. IT managers face the dual challenge of managing the existing storage resources and choosing the right approach to networked storage that best meets the organisation’s requirements.

The promise of an efficient storage management comes down to one simple question: Does it deliver the results that an organisation needs?

Currently, there are three main modes of external data storage—DAS, NAS, and SAN. Direct Attached Storage (DAS) continues to be the traditional mode of storage for many enterprises. Examples of DAS are a CD burner, a tape drive or an external hard drive, attached directly to the server. DAS is still popular with database administrators due to its ability to quickly replicate high-availability applications. However, it requires new drivers to be added to increase storage capacity, which in turn causes network downtime.

On the other hand, Network Attached Storage (NAS) offers greater reliability and availability. Simply put, NAS is hard disk storage set up with its own network, instead of being attached to the department computer that hosts applications to a network’s workstation users. By separating storage access and its management from the department server, it can serve faster both applications programming and files as they do not compete for the same processor resources. The network-attached storage device is attached to a local area network (typically an Ethernet network) and assigned an IP address. The main server to the NAS file server maps file requests.

NAS consists of hard disk storage, including multiple discs in RAID (Redundant Array of Inexpensive Discs) and software for configuring and mapping file locations to the NAS device. NAS storage can be a step toward and included as part of a more sophisticated storage system known as a Storage Area Network (SAN).

SAN is a high-speed special-purpose network that interconnects different kinds of data storage devices with associated data servers on behalf of a larger user network. Typically, a SAN is part of the overall network of computing resources for a large enterprise.

NAS or SAN?

Due to their high-cost, SANs are used by large corporations.

NAS, on the other hand, is affordable and appropriate to organisations of all sizes. The accompany table is a detailed technical comparison between NAS and SAN:

Network Attached StorageStorage Area NetworkPrimary functionSpecialised server providing networked file service and data storage for clients and servers. Storage is accessed directly across a LAN or WANStorage is accessed across a storage area network. Primary function is to provide consolidated fibre channel storage for serversAppropriate applicationsIdeal for file services and client storageIdeal for general-purpose application server storage, including OLTP

Connectivity

Across LAN or WAN Through SAN to server to LAN or WAN Storage/backup resources Backup can be attached directly to mid-range NAS appliances or can be distributed and attached to LAN or WANCan be attached directly to server or across fibre channel fabricAvailabilityRedundant power supplies and fans are typically available. High-end NAS systems offer a no-single-point-of-failure architectureRedundant hardware and software components provide high system availability. A system can be configured with no single point of failureScalabilityMultiple NAS servers can be added to the network and additional storage can be added to mid-range NAS serversStorage can be scaled by the addition of fibre channel switches and storage devices

According to research firm International Data Corporation (IDC), trends for the period 2001–2005 indicate:

• DAS will decline by 12 percent per annum
• NAS will grow by 32 percent per annum
• SAN will grow by 20 percent per annum

Therefore, NAS is the segment where rapid growth is expected. Revenues from NAS products in 2001 amounted to $1.84 billion worldwide. This number is expected to grow by 32 percent annually to reach $5.58 billion by 2005.

NAS - a versatile option

A typical NAS solution can be implemented for a wide range of applications such as document management/data sharing, database management, imaging, graphics, accounting, human resources and library information systems, among others.

NAS enables file sharing among clients, offers data recovery, provides additional storage for servers, acts as a target for data backup and allows resource sharing. The total cost of ownership (TCO) of NAS is significantly lower due to lowered operational costs and it doubles as a storage-cum-back-up device.

Products like NAS offer lower cost per gigabyte, ease of installation, multi-level data protection, increased space utilisation, storage consolidation and better network utilisation.

Being hardware independent is a key benefit of NAS. It allows easy back-up facility on the storage device itself—an uncommon feature in other contemporary offerings.

Thus, NAS holds immense possibilities for users seeking a scalable, smart, and easy to handle solution for their information systems requirements.

The author is the president and head of Enterprise Solutions at ICICI Infotech. He can be contacted at hari.padmanabhan@icici-infotech.com