NAS vs SAN
Storage Networks
When we talk about NAS (Network Attached Storage) and SAN (Storage Area Network), we are talking about networks that focus on data storage. Now both SAN and NAS have different architectures.
NAS
It is a storage network that provides the member nodes with the ability to share the same storage via an Ethernet connection. The computers that incorporate this system can access the data without the need for intervention from the application server.
SAN
It is a data network that provides access to consolidated storage. It is responsible for connecting the servers to their logical disk drives (LUNs). In the computer, a new connected hard disk will appear which will be the SAN. You could say that it is a virtual storage system.
Differences
The main difference between these two networks is, the one seen in the image below. In NAS we have some PCs that are connected to another network device (SAN). Meanwhile in SAN we have PCs that are connected in the same local network and to the same storage unit. This connection is usually made through fiber.
NAS vs SAN
|
NAS |
SAN |
|
Single storage device serving files over Ethernet |
Single storage block connected to other devices via a fiber cable |
|
A server (NAS) appears connected via TCP / IP connection |
A new hard disk (SAN) appears connected |
|
It is focused on systems that do not require a large volume of data. |
More focused on constant backups. |
|
Due to being an Ethernet connection, packet segmentation is required, adding certain latencies due to packet delays and losses. Keep in mind that until all packages are received, the information will not be available |
Being a hard disk connected via fiber optics adds a lot of speed and the data won't require packet segmentation reducing latency. |
Looking at the table, one can see that SAN is superior in all aspects in comparison to NAS, (higher speed and lower latency). Additionally, SAN scales really well.
But, what about NAS? Well, it's simple, NAS is a much cheaper alternative that only requires a server with a lot of storage connected to a Switch which is then connected via Ethernet to all devices in the network. Meanwhile, SAN uses fiber optic and connects directly to devices thanks to a fiber optic switch. This makes it much more expensive to maintain and manage, because it requires a change in architecture and structure.
Rafael & Alba