What is Network-Attached Storage?
What if you personally wrote one of the 70,000 songs on your 1TB local storage disk and want to share it with your family? But with their busy schedules, sitting everyone down at the same time to listen to your masterpiece isn’t practical, and the file’s too large to email or to send via WhatsApp. (It’s an hour-long symphony!)
In this scenario, the 1:1 relationship of your local disk storage to your server limits your ability to share the data from that storage. It’s too local. “Network-attached storage” (NAS) makes sharing data possible. It’s file-level storage that’s attached to a “local area network” (LAN) via a standard ethernet connection. Everyone authorized to be on the network has access to everything that’s on the NAS device, which provides a centralized location for storage and backup. So, your song is there for everyone to listen to whenever they’re free. NAS has similarities with cloud storage services such as OneDrive and Dropbox, but with NAS your data is stored on a physical device (not in the cloud) that’s owned by you (not by a third party) and over which you, therefore, have full control. For these reasons NAS is sometimes called a “personal cloud”. Cloud storage is essentially a large NAS managed by a vendor who gives you access to it on payment of a subscription fee.
In a business setting, NAS is similar to a “private cloud”, giving employees the ability to collaborate in real-time, with round-the-clock remote access to company data from any device.
Because NAS units are dedicated to serving files, they don’t have keyboards or monitors and use a stripped-down operating system fine-tuned for data storage and file sharing. Some come with one or more hard drives already installed; with others, you can purchase the hard drives separately according to your specific needs. Storage capacity can be increased by adding more hard drives, which can be done without shutting down the network. A NAS device with more than one hard drive can be used for data backup: data is duplicated on “redundant” drives (i.e., drives that are not being used). The term “RAID” relates to this type of backup.
A NAS device will have its own IP address, and, in addition to storing data, will provide a file system by which the data is organized. As with local disk storage, protocols are used in NAS to enable communication between devices. NAS usually uses the Transmission Control Protocol/Internet Protocol (TCP/IP) to transfer data over the internet: TCP bundles data into “packets” and ensures that they are reliably sent; IP standardizes the way data is addressed and routed. The “HTTP” or “HTTPS” that you usually see at the beginning of web addresses in a browser is part of TCP/IP.
The file system provided and managed by the NAS device also needs to follow a network protocol to be accessed. Commonly-used file system protocols used on NAS devices are NFS (Network File System), which is a frequently used on Linux and Unix systems; SMB (Server Message Blocks), which is mainly used with Microsoft Windows systems and is sometimes referred to as CIFS/SMB as it developed from the Common Internet File System; and AFP (Apple Filing Protocol), which is used with Apple devices. We will speak more about NFS a few sections from here.