SAN, NAS, DAS: differences

In terms of data storage, it is sometimes difficult to identify the differences between SAN, NAS, and DAS. Each has its strengths, and it all depends on the priority of the company or organization. For most modern organizations, data storage has become a major issue. Here are the differences between SAN, NAS and DAS.


The NAS server: a flexible and scalable storage

The NAS (Network Attached Storage), also called Network Attached Storage Server, can be a good alternative to Cloud Computing. The NAS server is a file storage device connected to a LAN (local area network). The NAS stores and retrieves data from a central point accessible to users who have permission to use the network. This network is available via Wi-Fi or Ethernet connection.

The NAS has definite advantages. It is flexible and scalable. If additional space is needed, simply add storage space by performing a very simple operation by adding nodes to the cluster. This server represents a kind of private cloud on site. Its hard disk has the same advantages as the Cloud. Moreover, it is both faster and more economical. The user has total control.

NAS and network connection

Like the Cloud, the NAS allows remote access to data via a network connection. It is therefore possible to work on the NAS wherever you are and at any time. All stored data is continuously available, which facilitates teamwork and allows for prompt response to customer questions. This server also makes it possible to follow the company's actions in real time since all the information is available in the same place.

The NAS server is configured through a web browser-based program. It is very useful for making backups and storing multimedia files. In case of an incident, the data can be recovered easily. The data is stored and protected before being transferred to the cloud.

The NAS server is a great improvement since it allows customers on a network to access the same files. This server is more and more used due to the emergence of Big Data. Companies now need to access their data centrally and this is what the NAS allows. The quality of customer service is therefore improved, and sales cycles are improved.

NAS is not only interesting for businesses. It can also be very attractive for families and individuals. In the multimedia field, the NAS has advantageous data protection features. The majority of the products offered include backup software that helps to copy important data from the PC to the network drive. There are NASs designed to carry multiple hard drives.

SAN and its advantages

The SAN (Storage Area Network) is a network dedicated to the interconnection of resources. It is composed of interconnected hosts, switches, storage elements and storage devices. It can span multiple sites.

The SAN presents storage devices to a host so that the storage appears to be locally connected. The presentation of storage to a host is achieved through the use of different types of virtualization.

This network is most often used to improve application availability and performance. It is possible to consolidate storage resources and provide tiered storage. The SAN also provides excellent data protection.

The SAN is based on Fibre Channel (FC) technology. Gateways can be used to move data between different SAN technologies. This network is mainly used to solve connectivity problems between multiple servers and storage units. It also enables disk and tape consolidation while facilitating the sharing of heterogeneous data.

If backup traffic is carried on this network, it relieves the main network of the burden of massive data traffic. It facilitates the consolidation of information in a centralized storage network. It also accelerates data retrieval. The transfer speeds are quite impressive. The SAN is capable of supporting a very large number of devices.


The SAN also simplifies backup and recovery. After an incident, it becomes very easy to quickly recover data. Data is mirrored at a remote site for seamless recovery. Data can be backed up to another site very quickly without affecting network performance. The SAN also supports several types of networking techniques.

Another important advantage of the SAN is that it is highly scalable. This is important in the case of rapidly growing networks. It is also very useful when storage capacity needs to be increased from time to time. Administrators can distribute storage among servers.

Both SAN and NAS allow the company to achieve significant savings. In both cases, IT staff requirements are greatly reduced. Both are increasingly affordable. The NAS server transfers pages and has low latency, while the SAN transfers blocks of information instead of individual pages.

When it comes to interoperability, the NAS environment is not a problem, while the SAN is just beginning to address the interoperability challenges it has always faced.


DAS: another storage device to consider

DAS (Direct-Attached Storage), also called direct-attached disk, is another solution to consider for companies. It is a storage device that is directly attached to a computer. It is not accessible to other computers. For example, the internal hard drive of a computer or server represents DAS storage.

Within a company, a disk connected to a server is considered to belong to the domain of Direct Attached Storage. It is generally accepted that DAS is able to provide better performance than NAS and SAN, since there is no need to go through a network to perform data transfer. As a result, many applications prefer DAS storage.

In the past, DAS caused difficulties because of a relative lack of efficiency since block storage could not be shared between servers. It was also difficult to administer. Indeed, since storage was not shared between servers, as is the case with NAS and SAN, it was necessary to manage as much storage space as there were servers, which was a very complex operation.

However, things have improved over the years. New distributed storage technologies have developed that have put DAS back on the map. Technologies such as VSAN, ScaleIO, Nutanix, and Ceph, among others, have helped make the DAS popular again.

It is now possible to aggregate multiple servers with large quantities of DAS disks. It is no longer difficult to create large storage bays. In addition, with its Flash memory disks (SSDs), DAS has very low latency, which makes it very attractive for businesses.

If you need to optimize the processing of your data, Ryax will accompany you from the beginning to the end of your project.

The Ryax Team.