NAS Recovery
RAID Recovery Guide
USB Drive Recovery Guide

© 2011 - 2024

What is NAS?

NAS (Network Attached Storage) is a standalone storage device containing one or several disks and providing access to the stored data via the network. NAS systems are very popular among users worldwide because at home such devices help replace shelves with CDs and in small business they can be a replacement for the server managed by an administrator. Moreover, storage device vendors - QNAP, Synology, NETGEAR, Buffalo, Seagate, Iomega, Lenovo, D-Link, Western Digital, Thecus - offer various configurations for all occasions; some even include units suitable for industrial applications, rack-mount and all that.

Typically, member disks in a NAS are arranged into a single, redundant storage with the help of the RAID technology. The main NAS characteristics:

  • The way of connection. NAS is connected through the network. There are devices that are very similar to NAS except the way they are connected to the host system (such devices use USB, FireWire, Thunderbolt, eSATA and whatnot). These devices are not true NASes, but USB-or-something-else hard drive enclosures.
  • Components. NAS can use typical PC components such as Intel Atom CPU in QNAP (e.g. model 859) or in some Synology models. Also they can use ARM or PPC CPUs.
  • OS. Typically, Linux is used to control NAS regardless the CPU type.
  • RAID software and filesystem. Because NAS uses Linux this means it uses MD-RAID to create and manage RAIDs. As for the filesystem, it is either selected by user or set by a NAS vendor. Typically, it is one of the following: ext3, ext4 (QNAP, Synology, Thecus, and early NETGEAR) or XFS (in Iomega and Buffalo NASes). Late models may use BTRFS filesystem (NETGEAR ReadyNAS series); some higher-end units use ZFS (NETGEAR ReadyDATA series).
  • NAS is not much different from a server or HTPC. Generally, NAS is not supplied with a keyboard, a mouse, and a monitor, although there are often ports to connect these if need be, same as in a typical server. On top of that, the main goal of NAS is to store data while a web server is designed to serve the website content.