Difference Between SAN and NAS

June 2022 · 4 minute read

The main difference between SAN and NAS is that the SAN is a high-speed network that stores and provides access to a large amount of data while the NAS is a centralized location that stores and allows the devices in the network to access data. 

SAN and NAS are two of the various storage mechanisms are used in computer networks. SAN is a storage network that provides block level data storage. NAS is a file-level data storage server that stores and provides data to connected devices in the network. SAN is more scalable, reliable and has higher performance while NAS is simple and easier to manage and construct.

Key Areas Covered

1. What is SAN
     – Definition, Functionality
2. What is NAS
     – Definition, Functionality
3. Difference Between SAN and NAS
      – Comparison of Key Differences

Key Terms

NAS, Network Attached Storage, SAN, Storage Area Network

Difference Between SAN and NAS - Comparison Summary

What is SAN

SAN stands for Storage Area Network. It is a high-speed network that stores and provides access to a large quantity of data. In other words, it is a dedicated network that is used for data storage. The data is shared among multiple disk arrays. The entire network consists of multiple disk arrays, switches, and servers.

Difference Between SAN and NAS

Figure 1:  SAN

SAN provides many advantages. As there are multiple disks to store data, SAN is more tolerant to failures. Failure in one disk will not affect the data accessibility of the other devices. It is also easier to add more storage space without interrupting the network. Therefore, SAN is more scalable. 

Moreover, the devices of the SAN are connected using fiber channels. They provide speeds of 2 to 128 Gigabits per second. Therefore, it is a high-speed network.  Some SANs use ISCSI (Internet Small Computer System Interface) instead of fiber channels. Those networks are lower in speed but are less expensive than fiber channels.

What is NAS

NAS stands for Network Attached Storage. NAS can be used if it is required to store data in a cartelized location where the data can be accessed by any device in the network. It consists of multiple hard drives in a RAID configuration for redundancy.

Main Difference - SAN vs NAS

Figure 2: NAS

NAS has a Network Interface Card (NIC) which is attached to a router or a switch. Therefore, the other devices in the network can access the data stored in the NAS. Devices such as desktops, laptops, and servers can access this data. The devices in the network access the NAS as a shared drive.

Usually, NAS is used in small to medium size businesses. The major disadvantage of NAS is that it is not tolerant to failures. For example, if the power supply of the NAS fails, the other device will not be able to access the data.

Difference Between SAN and NAS

Definition

SAN is a storage network that provides access to consolidated, block-level data storage. NAS is a file-level computer data storage server connected to a computer network that provides data to a heterogeneous group of clients.

Stands for

Storage Network Area is the long form of SAN while Network Attached Storage is the long form of NAS. 

Besides this main difference, below listed are some of the other important differences between SAN and NAS.

Fault Tolerance

SAN is more tolerant to failures than NAS.

Type

While SAN is considered a local hard drive, NAS is considered a shared network drive.

Scalability

Since it is possible to add more storage area to the network in SAN, SAN provides more scalability than NAS. 

Speed

As SAN uses fiber channels to connect the devices it is a high-speed network than NAS.

Redundancy

SAN is more redundant than NAS.

Method of Storage

While SAN uses block-level storage, NAS uses file-level storage.

Complexity

NAS has simple configurations, and it is easier to use. However, SAN is more complex. 

Cost

SAN is expensive whereas NAS is less expensive.

Management

It is difficult to manage SAN than NAS.

Usage

Large business organizations use SAN while small to medium business organizations use NAS.

Conclusion

SAN and NAN are two storage mechanisms in computer networks. The difference between SAN and NAS is that the SAN is a high-speed network that stores and provide access to a large amount of data while the NAS is a centralized location that stores and allows the devices in the network to access data. 

Reference:

1. “Storage Area Network.” Wikipedia, Wikimedia Foundation, 24 Aug. 2018, Available here.
2. “Network-Attached Storage.” Wikipedia, Wikimedia Foundation, 24 Aug. 2018, Available here.

Image Courtesy:

1. “SAN” by Silver Blue (CC BY 2.0) via Flickr
2. “Network-attached storage (NAS)” (CC BY-SA 3.0) via Commons Wikimedia

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