CertiGuide to Network+  9  Chapter 0110: Network Operating Systems (NOS)

RAID Volumes 1 Pop Quiz 0110.10

Network attached storage, or NAS, takes the RAID concept of encapsulating reliable disk storage in an easy-to-use package one step further. NAS devices are “dedicated” (single-purpose) file servers whose only purpose is to store data to disks, and retrieve it; using popular NOS file server protocols. And that’s it. That’s all they do. The limited functionality makes them often more reliable and faster (as well as cheaper) than file servers which are general-purpose CPU’s running general-purpose NOS’s.

Another benefit to the use of NAS devices is simplicity of administration. When an organization wants to add storage, they can buy a NAS box, plug in a network cable, configure the NAS box’s network address and file storage parameters… and start using it! There’s no need to select the desired components of an OS, search the Internet for the latest drivers and security patches for the OS, etc.

Most NAS server devices are sold with at least one hard disk, which is usually SCSI or IDE, depending on what that particular NAS server supports. Many NAS servers can be expanded by replacing the included hard disk, or by adding more disk drives into open storage bays in the NAS server’s cabinet.

Clients access data stored on a NAS device the same way they’d access data stored on a file server. For example, in the Microsoft Windows world, you might map a drive letter to the sharename made available by the NAS device, or browse Network Neighborhood and then open the desired file using Windows Explorer. In the Linux or UNIX world, you might use the mount command with –tnfs to direct your client to connect to data shared by using NFS.

RAID Volumes 1 Pop Quiz 0110.10