What is a SAN?

Storage area network, or SAN, refers to a high-speed network that provides block-level access to storage devices. It is a dedicated network that allows multiple servers to access shared pools of storage devices simultaneously.

SAN represents an upgrade from traditional file-sharing networks like Local Area Networks (LAN). Besides offering more storage capacity than traditional methods can handle, SANs facilitate separate connections between servers and storage devices using an array of protocols.

The key feature that sets SAN apart from other storage methods is its block-level operations — transferring raw volumes of data blocks at once rather than files. This helps applications perform better while improving accessibility, creating a more seamless IT flow.

Protocol options with SAN infrastructure include Fibre Channel (FC), Internet Small Computer System Interface (iSCSI), Fibre Channel over Ethernet (FCoE), among others. Each comes with unique capabilities suited for different organizational needs, to be explored later in this article.

The theoretical definition of storage area network comes to life when you look at real-world applications of SAN storages across a range of business sectors and industries. In essence, where vast amounts of data need to be processed, stored, and retrieved, SAN has its part to play.

What storage area networks are used for

As digital infrastructure continues to grow and ever more data accumulates, the application of SAN or storage area networking is becoming more extensive. Although primarily used for data storage, SAN now has additional purposes that cater to a variety of needs in dynamic IT and business environments.

Collaboration across networks: A significant advantage of SAN over traditional DAS (direct attached storage) is improved accessibility. The SAN architecture allows any network device to access stored data as if it’s on the local hard drive, making file sharing more manageable within networks spread across different geographical locations. This enhanced accessibility eliminates physical limitations, promotes collaboration between teams in any location, and significantly speeds up work processes.

Disaster recovery plans: Large enterprise-grade companies will often deploy replicated SANs so that each byte written in a primary disk can be mirrored into an off-site external disk using synchronous replication. This ensures minimal downtime and maximum availability in the face of natural disasters or other unforeseen events affecting the main site.

Virtualization: SAN has become indispensable for high-scale virtualization projects that enterprises are undertaking today. By hosting multiple operating systems or applications on individual servers, companies can consolidate resources and optimize server usage while reducing hardware investment costs.

Distributed applications: SAN’s scope of capabilities also extends to complex distributed applications like Oracle databases that demand many parallel accesses from numerous nodes simultaneously. With a volume management feature that is characteristic for most SAN instances, administrators have far more granular control over replacing failed disks, and moving volumes between arrays — all with transparency for users and without causing any interruption in services.

While popular among larger corporations, even small to medium enterprises are utilizing SANs for its flexibility and scalability. With the ability to add capacity on demand, SME spaces can leverage this technology to effectively manage their business-critical data without making substantial upfront investments.

How a SAN works

The operation of a storage area network relies on interplay between various components including servers, switches, and storage devices — all coordinated for optimal data management.

A SAN works by linking together storage devices and servers over an exclusive high-speed network. This designated network leverages fiber channel connectivity to ensure swift transmission of data.

This is not just any ordinary network; rather, it is known as “SAN networking”, a process devoted exclusively to rapid and secure transfer of important data between various storage entities in your computing environment.

If you were to look under the ‘hood’ of a typical storage area network, these are the sequences you would find that demonstrate how a SAN works:

  1. The process begins whenever you request to retrieve or save certain data on your computer.
  2. The application hosted on your server translates this request into an Input/Output (I/O) command.
  3. This I/O command gets converted into a more readable block-based format that understands and correctly addresses its destined location within the storage network area.
  4. To ensure unimpeded passage and prompt delivery, these blocks of data are encapsulated inside frames accompanied by vital information like source ID, destination ID, etc.
  5. With the SAN switch, each frame smoothly navigates through complex paths and intersections within the network storage area.
  6. These frames finally reach their respective addresses, whether it be disk drives or tape libraries based on their intended destination.
  7. After ensuring successful reception at their destination nodes via acknowledgments, these frames get disintegrated back to blocks of raw data (a bit like unpacking parcels at their final destination).

Every component involved — from servers down to individual disk drives — has unique identifiers that make it recognizable within the high-speed storage area network. The combination of seamless functionality among disparate components supports unprecedented flexibility in data management.

Storage area networks create a buffer for the potential chaos that could result during peak data transfer requests. SAN consistently delivers system-wide efficiency, enabling IT teams to focus on more sophisticated applications without worrying about performance bottlenecks. A key function of SAN, therefore, is to provide reliable access to consolidated block-level storage that is scalable for growing IT demands. 

Advantages of a SAN

SAN, or storage area network, offers robust benefits for data storage and accessibility across organizations. Let’s break down the advantages of a SAN and see just why it has been gaining traction in managing vast volumes of data.


Organizations dealing with ever-increasing amounts of data can readily expand their resources without embarking on comprehensive system rebuilds. A SAN enables you to easily allocate additional storage to servers, allowing your business operations to continue seamlessly even during periods of significant data growth.

High availability and resilience

Relying on a network architecture designed for fault tolerance, SAN ensures constant access to mission-critical data at all times. This comes hand in hand with rapid disaster recovery, since the devices offer options for replication or snapshots that ensure smooth business continuity despite hitches.

Improved data transfer speeds

SAN optimally reduces latency, supporting exceptional speed and performance. This is incredibly valuable in environments where high-speed processing is inevitable, such as businesses handling real-time applications.

Simplified IT management tasks

System administrators using SAN have the flexibility to centralize storage needs. This eliminates the need to manage individual drives attached to every server, making monitoring and maintenance far more efficient.


Distance connectivity offered by different types of SAN storage connections allows off-site data replication, significantly enhancing disaster recovery plans.

Improved security

Standalone storages are frequently compromised by cyber threats. High-quality SAN devices offer superior security measures, with top-notch standards for access controls and encryption techniques, helping to reduce vulnerability risks from unauthorized entities.

By understanding what a storage area network is and its significant advantages, it is clear why businesses are seeking out SAN for their data storage needs. A comprehensive SAN approach not only offers the above-mentioned benefits but also paves the way to future-proof data storage and operations in a fast-moving digital environment.

SAN disadvantages to look out for

While storage area networks hold significant advantages, like any technology, they come with their set of drawbacks as well. Let’s now explore the SAN disadvantages and notable concerns.

Cost factor

SAN infrastructure can be expensive to implement and maintain. It requires not only specialized hardware but also trained personnel to manage it effectively. Enterprises should carefully assess their needs before investing in a SAN solution, considering long-term operational costs along with initial expenses.


SAN environments are complex by nature, designed to serve comprehensive storage requirements with efficiency. This sophistication comes at the expense of ease-of-use. Managing a SAN involves dealing with complex configurations and processes that often necessitate involvement from experienced IT professionals.

Scalability issues

While a SAN is scalable theoretically, it will mostly depend on organization-specific factors, such as budget constraints and physical space for additional hardware placement. Issues around scalability may arise over time with SAN.


Potential vulnerability loops pose challenges as well. As with any network system, security must not be overlooked when employing a SAN setup. Measures need to be put in place to protect data from threats, both externally (ie. cyber attacks) and internally (ie. human error, accidental data loss).

While highly desirable for its data storage capacities and performance capabilities, the decision to implement a SAN should be made with care, only after considering the potential pitfalls and putting measures in place to mitigate them where possible.


In the field of storage systems, there are two key players that are sometimes confused: storage area networks (SAN) and network attached storage (NAS). While ‘network area storage’ could refer to either SAN or NAS, let’s take a closer look at the differences between them.

Architectures: SAN and NAS have fundamentally different architectures. The major distinction stems from how they deliver data to clients. A SAN essentially operates as a standalone network exclusively for storage devices, whereas NAS connects through an existing ethernet network.

A SAN provides block-level access to stored data, making it akin to direct attached storage that has been extended into a networked environment. On the other hand, a NAS delivers file-level access, acting as if it were just another device on your current LAN setup sharing files.

Data delivery mechanisms: The differences in operation between the two systems leads to differences in their data delivery mechanisms. With block-level operations in play, applications running on client systems view a SAN-attached storage device as being locally attached within their own context.

In contrast, NAS devices serve data over standard TCP/IP networks using high-level file-based protocols such as NFS or SMB/CIFS. This positions them closer to traditional file servers.

Performance characteristics: Given SAN’s sophisticated architecture and more direct hardware connection path through fiber channel technology, SAN often boasts higher levels of performance in terms of latency and throughput compared to NAS.

Understanding the distinction between SAN and NAS — two standout types of network area storage — is critical for any organization trying to evaluate their data infrastructure needs. Both storage types come with pros and cons, depending on specific use case scenarios, so choosing between them should be based on a thorough understanding of their complexities, benefits, and challenges.

Types of SAN storage connections

SAN storage connections facilitate data transfer between servers and storage devices within a network. Broadly speaking, there are three types of SAN connections that you might come across in your SAN operations:

  • Fiber channel: If performance tops your priority list, fiber channel is a good fit, due to its high speeds and efficient error correction mechanisms.
  • iSCSI: Cost-effective yet practical, this option should appeal if you are looking to create economical yet sufficiently speedy data pathways within your network.
  • FCoE: This connection type is an optimal combination of economy and performance, ideal if you’re looking to optimize costs without heavily compromising network speed or efficiency.

Each SAN storage connection type brings unique advantages and implications for how your SAN will operate. Elements such as infrastructure costs, speed requirements, and future scalability are all important factors to consider when deciding on the best connection method for your specific needs.

SAN switches

A SAN switch is a high-speed device that connects servers and storage devices in a storage area network. It efficiently directs data traffic between multiple servers and storage units, ensuring reliable and high-performance data transmission within the network.

SAN management

Understanding storage area networks management is crucial for ensuring efficient allocation and utilization of data storage resources. SAN management is an IT function that involves overseeing and organizing SAN operations, including capacity allocation, performance optimization, security enforcement, and issue resolution. Core functionalities of SAN management include:

  • Monitoring health and performance: Keeping track of SAN health and performance to address potential issues promptly.
  • Resource provisioning: Allocating storage space based on server requirements for optimal performance.
  • Security and compliance: Ensuring data security and compliance with regulatory standards.

Effective SAN management offers numerous benefits, such as improved efficiency, enhanced application availability, centralized information, simplified management tasks, and secure data access. Whether a small business or a large enterprise, proficient SAN management is essential for robust IT infrastructure. Tools like Atera offer a comprehensive solution for SAN management for organizations of all sizes.

Atera supports comprehensive SAN management

Analysts project that the storage area network market size will rise steadily in the coming years, reflecting the significance of SAN implementation among enterprises worldwide.

When it comes to managing a storage area network, using the right software and tools is critical.  Atera is an all-in-one remote IT management solution that provides comprehensive support in managing your SAN environment. The features and benefits that Atera brings to SAN management include:

  • Centralized management: The remote IT management suite provides access to monitor and control your entire network from one console.
  • Real-time alerts: This feature instantly alerts the IT team to any fluctuation or anomaly with your SAN, helping to keep deficiencies at bay.
  • Comprehensive reports: Rich insights coupled with data analytics about storage utilization, performance metrics, and more, to ensure the health of your SAN infrastructure.
  • Automation: Atera’s proactive automated approach enables IT teams to automate routine checks, helping to alleviate the day-to-day routine. 
  • Predictive analytics: AI-powered insights help IT professionals to foresee potential issues before they adversely impact operations.
  • Easy use: The Atera interface is based on intuitive design and navigation, bringing all these features to life even for new adopters. With add-on integrations, IT teams can further customize the platform for their SAN management and IT management needs.

Using an advanced tool like Atera helps ensure reliable storage performance and minimal downtime while simplifying the whole process of SAN management. When deployed correctly, Atera is much more than a monitoring tool; it’s like having another expert team member driving optimal SAN management around the clock.

Start your free trial today and discover the potential of Atera for your SAN management success.

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