Network Attached Storage (NAS) is a fast-growing technology in today’s data driven world, and has become something of a buzzword as it gains popularity. But what exactly is NAS? How does it differ from a file server? What benefits does it offer and what is RAID? What drives should one use in a NAS enclosure? Why is this important? Knowing your NAS is important to leveraging this technology to its full capability, ensuring your data is protected and available whenever you need it.

What is NAS and how is it different from a server?

NAS is computer data storage that is connected to a computer network, enabling data storage and access to all users and devices on the same network. In other words, it offers a centralised data repository for multiple users and devices. In this way, it offers the same functionality as a file server, however, it also provides additional benefits.

NAS enclosures are specialised computer appliances, built and designed specifically for storing, accessing and sharing files, whereas a file server is often a regular desktop computer that has been configured to act as a server. Because NAS devices are purpose-built for data sharing, they offer a number of benefits, including faster access to data, simple configuration and easier administration. It also removes the file-server function from general-purpose servers, speeding up performance. NAS enclosures also have the capability to incorporate multiple hard drives into a single system. This not only offers massive storage capacity, but also provides the capability to create redundant storage using RAID.

What is RAID?

RAID refers to a ‘Redundant Array of Independent Disks’, which uses multiple disks to improve performance, increase storage capacity, improve fault tolerance and safeguard data. Using RAID technology, data can be mirrored on one or more disks within the array, ensuring that should one disk fail, the data will be protected. Using a technique called ‘striping’, RAID also creates the ability to read or write to more than one disk simultaneously, which helps to improve performance. In addition, because RAID uses multiple disks that are viewed as a single device by users accessing the NAS system, it provides dramatically increased storage capacity compared to a single disk.

There are many different RAID architectures, known as levels, each of which provide a different balance of performance and fault tolerance. Some of the most popular RAID configurations are RAID-1 and RAID-5. RAID-1, also known as disk mirroring, uses at least two drives that duplicate the storage of data, which basically creates two copies of the same data, ensuring that should one drive fail, the data will not be compromised. RAID-1 does not use striping, but read performance is improved because both disks can be read at the same time.

RAID-5 requires at least three, but usually five, disks. The data is distributed across the total number of disks, which increases performance and provides redundancy. In a five disk array of 1 Terabyte (TB) drives, 4TB will be dedicated to storage, and if one of the disks fails the data from the remaining drives can be used to reconstruct the data from the failed drive on the remaining 1TB of capacity. Performance will be decreased while a failed drive is present, but no data will be lost. The only way to lose data in a RAID-5 array is if more than one drive fails simultaneously. RAID-5 offers increased disk performance and the ability to lose a single drive to failure without affecting data.

Choosing a NAS enclosure

NAS enclosures are typically available in 1-5 bay and 6-12 bay systems, which in simple terms means that if you include 4TB drives, you could potentially have up to 20TB of storage in a 1-5 bay system, and up to 48TB in a 6-12 bay system. However, with the different RAID configurations this is not generally the case.

Choosing a NAS enclosure requires firstly an examination of how much storage space is required, and then a decision on the level of RAID to be used, which will affect the available capacity. The 1-5 bay systems are typically aimed at the Small Office Home Office (SOHO) market, while the 6-12 bays are ideal for the Small to Medium Business (SMB) market.

Selecting the right drives for your NAS

It is important to bear in mind that regular desktop drives are not designed to be used in NAS enclosures. Not only do these drives typically not support RAID, they also do not provide the levels of performance and reliability required in a NAS environment, which means that they will be more likely to fail. WD has simplified the process of selecting hard drives for use in NAS with the WD Red and WD Se range of hard drives.

WD Red has been designed specifically for use in 1-5 bay NAS systems, tested for compatibility with a wide variety of NAS enclosures. The drives also feature WD NASware 2.0, which further improves drive reliability and protects data in the event of a power loss or power disruption. WD Red drives are available in capacities of up to 4TB, and are also available in 2.5-inch drives up to 1TB for small form factor NAS systems.

WD Se drives offer optimal storage for large scale NAS as they have been designed to run 24x7 and offer performance, reliability and massive capacity in a cost-effective platform. They are designed for use in 6-12 bay NAS systems, are available in capacities of up to 4TB, and feature a five year limited warranty.

To conclude

NAS is a dependable, expandable, and easy-to-install solution for shared data storage and access. Choosing the right NAS system and the right drives to include in the enclosure will ensure data is available, redundant and easy to access, while providing high capacity shared storage in a variety of environments.

By Ruben Naicker, WD Product Specialist at DCC