Difference between NAS and SAN and their storage architectures

NAS and SAN both provide network storage for business and choosing one over the other isn’t as simple as it seems. NAS vs SAN is a discussion that comes up a lot and often baffles users. Along these lines, the blog explains the difference between NAS & SAN Storage.

NAS (Network Attached Storage) VS SAN (Storage Area Network)

Organizations require a reliable network storage system where

data can be stored and is readily available. Both NAS and SAN provides network storage solutions for business. However, they may seem similar at first yet differ a lot.

NAS (Network Attached Storage): NAS is file-level computer storage connected to a network that provides access to a centralised location. NAS storage device operates on data files.

SAN (Storage Area Network): SAN is a dedicated network that interconnects multiple users to access block-level data storage. SAN is a local network of multiple devices.

Factors which determine using either of the network storage solutions:

The major difference between NAS and SAN storage usage depends on:

• How they are connected to the system (connection established between the accessing system and storage device)
• Type of data that you want to store
• How communication is done with the device i.e. cabling used to connect the system (Fibre Channel, Ethernet, etc.)
• Usage pattern
• Scaling concerns
• Budget
• How input/output requests are conducted i.e. SCSI, CIFS, NFS, etc.

Difference between NAS and SAN Storage

	NAS (Network Attached Storage )	SAN (Storage Area Network)
Definition	NAS storage is based on Transmission Control Protocol/Internet Protocol (TCP/IP) and uses the file system	SAN uses a Fibre Channel (FC), which is a high-speed network of storage devices connected with servers.
Data Access	File-level	Block level
Connection	Implements NFS, HTTP, and CISF protocol to share files	Fibre Channel or server class SCSI
Identification of Data	Data is identified by file name; byte offsets transfer meta-data or file data	Data is identified by disk block number, transfers raw disk blocks
Information Sharing	Offers greater sharing of information	It is operating system dependent
File Management	By NAS head	Server manages the File System
Backups	Backup and mirror are done on files which save bandwidth and time	Performs disk-to-disk backups. It treats the storage array as a virtual tape library
Budget	Provides solid performance for organizations with smaller budget	It uses fibre channel and fast data transfer; hence, SAN environment is pricy

Typical Usage: NAS vs SAN

NAS:                                                                      

• File serving
• File sharing
• Content archiving
• Metadata directories
• Peer-to-peer data sharing Data replication

SAN:                                                                      

• For large database servers
• For clustering configuration
• Recovery archives
• Sharing of backup (libraries)
• Data replication

To sum up

The usage of NAS and SAN architecture depend on the requirements and system format. For instance, NAS is primarily used for long distance read/write operations, on the other hand, SAN is used for higher performance block level data storage. Furthermore, with the rapid advancement in data storage technology, there is a greater demand for flexibility, performance, and scalability which both the network storage systems are capable enough to deliver.