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Follow UsThe constant need to back up files can cause bottlenecks and waste precious bandwidth for storage purposes. As a result, archiving of data has taken predominance over other business needs in enterprises. Though the LAN concept with server-based storage did address some of their needs, still there was a need for a far more high-speed and ever-complex storage management. And the answer to this problem was addressed in the form of Storage Area Networks (SANs).
Storage Area Network
These new methods assure of better performance and availability. They can interconnect mainframe disk or tape to network servers or clients, and can create parallel data paths for high bandwidth computing environments. A SAN is another network that differs from traditional networks as they are fabricated from storage interfaces. For the same reason, SANs are often referred to as the network behind the server.
Need to implement SAN
We are aware that for any kind of computing, data/information is the key and they form the underlying resource for conducting any kind of process. Information forms the vital asset for any enterprises. Data is stored on storage media, and these media are accessed by applications executing in a server. Traditional means for connecting servers and storage can no longer satisfy today''s requirements for fast access to massive amounts of data. According to web source which says that given the amount of data to be managed and made available in many organizations increasing at a 60% annual rate, the reason for implementing a SAN is more than justified. According to many industry experts, the main reasons that can be attributed are:
SANs are cost effective:
- Reduced cost of storage management, including backup & recovery.
SANs reduce business risk:
- Faster disaster recovery,
- Reduced revenue loss from downtime.
- Reduced lost opportunity costs.
Legacy investments are protected
- Can be implemented without abandoning existing storage infrastructures such as devices using SCSI connections
SANs provide scalability
- Suitable for work-groups yet expandable to support enterprise data centers.
- Add servers and storage independently
SANs allow flexibility
- Reconfigure Storage and Servers on the fly.
- Load sharing and redistribution.
SANs enhance overall system performance
- More effective use of existing server compute cycles.
- Real-time backup without impacting LAN/WAN.
- Provides multiple server to storage paths.
- Networked storage arrays will outperform bus-attached storage.
- Compatible with parallel database applications.
SANs are an integral part of any High-Availability plan
- Facilitates shared on-line spares and remote backup or mirroring.
- Reduces downtime requirements.
- Storage is independent of the application and accessible through alternate data paths such as found in clustered systems, even in "shared nothing" architectures.
SAN Topology
SAN combines, the LAN networking models with the core building blocks of server performance and mass storage capacity and thus eliminates the bandwidth bottlenecks and scalability limitations imposed by the SCSI (small computer system interface) bus-based architectures.
Enterprise Storage Topology (Traditional Mode)
In the traditional storage model, each server attached to a network requires its own dedicated storage. If a new server is needed in order to meet the requirements of a network, it is also necessary to add dedicated storage for that server. If additional storage is necessary in order to support the demands of one more server, it has to be added specifically for that server, even though an adjacent server may still have available storage capacity. (Fig source: InfraStor technologies)
Storage Area Network Topology (New)
The Storage Area Network operates behind the servers to provide a common link between servers and storage, allowing administrators to independently scale the storage or server processing power as depending on the need. It allows multiple servers to access the same data so that duplication of information can be reduced, and permits data backup to take place directly over storage channels, eliminating the bottleneck of the relatively slow LAN. Data is also more consistently available, as the failure of a single server will not cut off any storage from remaining servers. (Fig source: InfraStor technologies)
A SAN supports direct, high speed data transfers between servers and storage devices in the following three ways:
- Server to storage: This is the traditional model of interaction with storage devices. The advantage is that the same storage device may be accessed serially or concurrently by multiple servers.
- Server to server: A SAN may be used for high-speed, high-volume communications between servers.
- Storage to storage: This outboard data movement capability enables data to be moved without server intervention, thereby freeing up server processor cycles for other activities like application processing.
SANs allow applications that move data to perform better, for example, by having the data sent directly from source to target device without any server intervention. SANs also enable new network architectures where multiple hosts access multiple storage devices connected to the same network.
Benefits:
Some of the benefits include:
- Improvements to application availability: Storage independent of applications and accessible through alternate data paths.
- Higher application performance: Storage processing off-loaded from servers and moved onto a separate network.
-Centralized and consolidated storage: Simpler management, scalability, flexibility, and availability.
- Data transfer and vaulting to remote sites: Remote copy of data enabled for disaster protection.
- Simplified centralized management: Single image of storage media simplifies management.
Storage Area Networks (SANs) form an integral part of any enterprises in need of up-to-date high availability data. Well, they could be ISPs, large financial services company and practically every organisation with data warehouse in place.