Storage area network (SAN)

What is SAN?

A storage area network (SAN) is an at ease, high-pace information transfer network that provides access to the very last storage consolidation, information storage devices. Storage area Networks are generally made from hubs, switches, garage components, and storage gadgets which are interconnected with an expansion of technologies, topologies, and protocols

Why storage area network:

A single server can offer multiple difficult disk shared machines, massive networks may require extra storage than one server can provide. As an instance, big agencies might also have several terabytes of statistics that want to be available to multiple nearby place Networks. In this situation, you could install a storage area network as opposed to adding greater servers. because only tough drives need to be replaced rather than the best laptop structures, storage area network are a very good technique to boost network storage.

SANs Networks are the most typically used storage system structure used by agencies in business-associated programs that need high overall performance and low time. SANs permit agencies to apply more rigorous methodologies and tools for safety, records safety, and accidental recovery.

LAN limitations:

In a client-server architecture (LAN), in which storage device is legitimately associated with the server. If the storage device turns out to be full and we have to install another storage device to the server. This is the primary inadequacy in a client-server architecture. In this way, for this situation, we need to expel the past stockpiling storage and need to introduce another one. This is a time taking and expensive technique. Because the past stockpiling storage is squandered now.

SAN Working:

To prevent this work, SAN is introduced as a good technique. SAN is created by using a storage pool.

Storage pool:

A Storage Pool is a bundle of storage devices that are connected as a storage array. It is actually the shared storage environment from physical storage.

SAN is just a little bit different from LAN. In LAN the storage drive is directly connected through the servers, While in SAN The storage devices are connected separately as a storage pool. All data stored in this pool and seems like a hard drive is attached to the server.

Units of SAN:

There are two types of cables used in SAN.ie Fiber cable, copper cable

- Fiber cable:

These cables are used for fast transmission. Fiber Cable is further classified into single-mode fiber and double-mode fiber.

- Copper cable:

These cables are cheap compared to fiber. They have a low transfer rate as compared to fiber cables.

Hubs:

The communication devices used to communicate from one end to another end during fiber deployment known as hubs.

Switches:

Switches are also used for communication but they are better and cheap as compared to hubs.

Host bus adapter card:

HBA is deployed on all servers and storage devices to communicate in SAN implementation.

- Storage Zone:

All storage devices are connected to each other seems like a disk array.SAN implementation on disk array provides business continuity, good performance, and multiple host connections.

Types of SAN solution:

- Fiber Channel (FC):

In this implementation high-speed fiber switches used.This due to the fast transfer of data.

- ISCSI implementation:

ISCSI stands for an internet small computer system interface. This is a low-cost implementation based on low-cost IP networks.

- Fibre Channel over Ethernet (FCoE):

It has a low marketplace share (much less than five%). Like ISCSI, it places an FC body inside an Ethernet datagram and delivers signals through using an IP ethernet network.

- Non-unstable memory explicit over Fibre Channel (FC-NVMe):

NVMe, an interface protocol, is used to get admission to flash storage thru the PCI express (PCIe) bus. It helps several parallel queues and each of them is able to support tens of thousands of concurrent instructions. that is unique from conventional all-flash architectures supporting the handiest one serial command queue.

How to set up SAN:

SAN implementation is a little different from LAN. Firstly, The storage devices separately connected each other showing a shared environment or seems like a Storage pool. Then insert a fiber switch between server and storage pool. Connect every device of the pool with the switch using a fiber cable. Connect every server with a fiber switch using fiber cable. Attach a Host Bus Adapter card (HBA) on each server and pool to communicate. This is the easy set up of SAN.

Advantages of storage area network:

- Storage virtualization

The server is not attached to a single storage device. Huge and Shared storage pools are available for software applications.

- High-speed disk technologies

Fiber cable offers great data retrieval speed. The data transfer from storage to storage is available via direct data transmission from source to target which requires minimum server intervention.

- Centralized Backup

Servers seem that data is stored on the local disk. The system administrators can take back up from storage by using block-level and incremental level backups.

- Dynamic failover protection

If a server fails or offline for maintenance it enables its built-in redundancy and automatic traffic rerouting. Hence it continues it’s network operations

- Extendable

The storage device on SAN seems like a storage pool. If the storage pool seems full. Then a single hard drive can be attached to this storage pool. Hence the storage pool is extended now without loss of storage.

- Data Security

Data in SAN is sure and cannot be accessed by false users

Disadvantages of storage area network:

- Expensive

SAN is expensive because fiber cables and fiber switches are used in this implementation.

- Data leakage

As client computers use the same set of shared data then it is the possibility of a loss of sensitive data.

- Not good work with fewer servers

SAN is not good with few servers and high traffic. With few servers, it works well on low traffic

- Expensive

SAN is expensive because fiber cables and fiber switches are used in this implementation

storage area network Software

The SAN software controls the interface between client servers, connectivity devices, and storage pools.It controls all SAN components and interconnection devices. It also manages the mapping storage devices, switches, and logical SAN partition.