What is NAS, what is RAID?

Explanation of terms for beginners and interested parties

Standard Technology – What is NAS?

Centralised storage for your home or office

Understanding Network Attached Storage (NAS)

Network Attached Storage (commonly abbreviated to NAS) are hard disk storage devices which you can connect to your home or office network. They enable multiple computers in a network to share the same storage space at once.

ccess to the NAS device is over a computer network (usually via TCP/IP) rather than being directly connected to the computer (as in internal hard drives or external USB/SCSI drives).

The NAS devices are assigned an IP address and are accessed by clients (PCs or laptops) via a server that acts as a gateway to the data (this server is within the NAS device and hence NAS devices are often referred to as NAS servers).

Why use NAS?

Three main advantages for using NAS:

Expandability
Simply add another NAS device to expand the available storage if you need more storage space.
Fault tolerance
NAS brings an extra level of fault tolerance to your network. Fault tolerant measures such as RAID prevent the NAS device from becoming a point of failure. NAS systems often contain more than one hard disk drive; they are arranged into logical, redundant storage containers or RAID arrays for added redundancy/security – thus, protecting data in the case of disk failure.
File sharing
Whether you are a home, small office or business user, NAS devices allow you to share large amounts of data with other PCs or laptops in your network – easily, efficiently, and cost-effectively.

How can NAS benefit you?

Network Attached Storage (NAS) is becoming a powerful and proven technology for storing and sharing data in an office or home network. The increasing demand for NAS is fuelled by a number of factors:

Cost benefit
You can now add storage to your network without upgrading or replacing existing servers – which can be an expensive option. NAS offers an affordable and expandable solution for end-users requiring network shared storage in a home or office environment. NAS architecture allows you to add storage on the network without having to buy a new and bigger server or upgrading it. NAS is therefore, an effective strategy for extending your existing investment in server technology.
Administrative convenience
NAS offers a simple solution: store and share photos, files, music or videos from one central location and make it accessible to anyone with a PC or laptop in home or office network. NAS-based storage offers administrative features that simplify or reduce manual disk expansion and archiving functions, user and application partitioning, data protection, and other time-consuming storage maintenance activities.
Greater data reliability
NAS devices with more than one hard drive bring an extra level of fault tolerance to the network as many offer mirroring RAID features and functionality.

NAS from Buffalo

Network Attached Storage (NAS) is becoming a powerful and proven technology for storing and sharing data in an office or home network. The increasing demand for NAS is fuelled by a number of factors:

Buffalo’s award-winning family of LinkStation™ and TeraStation™ NAS devices provide a simple cost-effective solution to protect, manage, and share your critical information. They are designed for small to medium-sized businesses or homes that want to share central data. All Buffalo NAS, devices include Memeo™ AutoBackup software to manage your essential backups.

Standard Technology – What is RAID?

RAID is an acronym of “Redundant Array of Independent Disks”. The idea is to combine standard drives into an array which performs better than a single disk and at the same time your computer sees it as a standalone drive. This technology can be used in different ways to achieve different results called RAID Levels/Modes.

Why would you need RAID?

  • For Speed and Capacity
  • If you need Maximum Redundancy
  • If you require an increase in capacity with simple redundancy
  • For a perfect combination of speed and security

RAID Levels/Modes

There are several levels of RAID, all of which offer a certain level of fault tolerance and also have different levels of performance and functionality.

The two most common RAID levels are RAID 1 and RAID 5:

JBOD
The controller treats each drive as a stand-alone disk, therefore each drive is an independent logical drive with its own drive letter. Standard Mode does not provide data redundancy. It is not a RAID in the sense of the meaning. Nevertheless it is among the RAID levels because the RAID controller manages it.
RAID 0
RAID 0 or striping mode is used to achieve higher storage capacities with maximum speed. The data is split among several disks that are written at the same time. So for example 2 drives of 250GB capacity in RAID 0 are faster than a single 500GB drive.
RAID 1
RAID 1 or mirroring mode is used to make an exact copy of data on each disk in the array. In this mode the capacity is half the capacity of all the hard drives within the array.
RAID 5
RAID 5 or parity mode distributes data across multiple disks making the system fail proof. In this configuration the total capacity of the system is (N-1)*GB where “N” is the number of disks you have in the array, so for example four disks of 250GB capacity provides 750GB of total usable storage. In some more advanced systems is it possible to combine different RAID modes together.
RAID 10
Best used for speed and redundancy. It is a combination of Mode 0 and Mode 1 and gives the read/write speed of RAID 0 and the redundancy of RAID 1.
RAID 50, 51, 60 & 61
Combined RAID mode, available on TeraStation® 6 and 8 bays.