A NAS server is a network storage system that enables multiple users in LAN to access files via the Ethernet connection. NAS is a kind of external storage system. The device itself has no keyboard or display and is located in the local network as an independent network node with its own unique IP-address. System administrator can configure and administer NAS with the help of browser-based utilities.
NAS is used for the following tasks:
Backup from all user devices on the network.
Organizing all media files and documents in a manageable form, with easy access from any network device.
Deployment of web and mail servers.
Organizing shared data exchange hub between devices running on different platforms, e.g. Mac and Windows
Network Attached Storage (NAS) components and features
Physically, a NAS is a box with a motherboard and a RAID array of hard drives. One of the hard drives contains an operating system, usually Linux or FreeBSD with special software. Operating systems, RAM, cooling and other key components are not the only features that differentiate NAS from external hard drives, which store data passively.
Unlike these external drives, NAS provides granular access control for its users. You can connect to NAS via either Ethernet or Wi-Fi, although there are models that support USB. NAS helps automate data management as well as protect information from loss, natural disasters, etc.
The number of disks in a NAS is two or more, usually HDDs. There are storages based on SDD, but their operating costs are much more due to the necessity of using additional equipment such as high-speed routers, not to mention the SSDs themselves. NAS is managed remotely from the administrator's office PC via a Web interface or a special client.
NAS involves the use of file protocols such as NFS, AFP, or NCP.
DAS is an extension of an existing server drive. It is not connected to a network, which means you must have access to the physical storage to access the data. Because the disk is accessed via a dedicated channel and network traffic is not delayed, DAS offers higher performance.
The difference between a NAS and a SAN (Storage Area Network) is that a NAS provides not only storage but a file system as well. A SAN arranges storage resources into an independent, high-performance network. NAS deals with single file input/output requests, while SAN deals with contiguous data block input/output requests.
Despite their differences, SAN and NAS devices are not mutually exclusive and can be combined as SAN-NAS hybrids, offering both file and block storage protocols.
NAS vs. Cloud
NAS boxes are usually located in offices and allow direct access to data via the local network. The cloud server is always available over the Internet.
Modern NAS includes a cloud option that allows the user to access the data stored on it via the Internet, but its performance and capacity cannot compete with cloud services employing powerful servers and data centers.
The cloud provider owns cloud storage and the customer rents it and pays for the space provided each month. With NAS, you have to make a one-time investment and use it for free.
With a NAS, you have physical access to the disks and other hardware components. The device with the information is always in your possession. However, if the hard drives fail, you will lose all your data.
There is no such problem in the cloud. The provider regularly perform backup, so you cannot lose it at all.
Another difference: to get more storage capacity in NAS, you have to buy additional hard drives. However, such expansion has its limitations because of the limited number of allocated slots.
One more thing about cloud storage is that you do not have to worry about upgrades and buying additional equipment. Cloud is also more user-friendly compared to Network Attached Storage.