What is a Storage Area Network?
What does storage look like in a computing environment? Even if you’re strictly an end user, it can be tempting to think of the spinning plates of a hard disk drive in a desktop tower. Or, you might envision the solid-state flash drive in your laptop as a bigger, more permanent USB thumb drive. Local device storage is easy to understand.
If I asked you to think about the shared server storage that your company uses, you might then picture a closeted room somewhere deep in the heart of an office building filled with racks of blinking servers and weird cooling fans hiding in the dark. Or maybe you’d think of the Cloud and imagine it’s all living in some bigger version of that same thing out in the desert.
Wherever your mind goes, it’s unlikely that you’d immediately think of a Storage Area Network (SAN). These complex, highly efficient, and heavily managed systems provide the backbone of dedicated, dependable, and secure storage. Due to their complexity, these systems require an IT staff who truly understand storage and network architecture and have the skills to build a SAN — not to mention the budget to maintain it.
So what exactly is a SAN? And is it still the fastest, strongest storage option for business-critical data? Can the cloud compete? What is the future of enterprise data storage as the volume of data approaches infinity?
These are the questions that used to keep us awake at night, too.
What is a SAN?
Let’s start with the basics. A Storage Area Network (SAN) is “a dedicated, independent high-speed network that interconnects and delivers shared pools of storage devices to multiple servers.”
Traditional server-based storage offerings include Direct Attached Storage (DAS), storage physically attached to a server, or Network Attached Storage (NAS) with an array of storage devices all managed by one network head unit. SAN technology changes the game by distributing a system’s networking capabilities into a fabric. This format adds complexity, while reducing the potential bottlenecks and single points of failure.
In a SAN, each server has access to the entirety of shared storage, as if it were a drive directly attached to the server. With an intricate system of switches, cabling, and host bus adapters, the SAN interweaves storage arrays and servers into an interconnected network that optimizes performance and speed.
Another critical distinction between DAS/NAS and SAN storage strategies is the network protocol used to transport data across the enterprise. Storage Area Networks leverage Fibre Channel (FC) or iSCSI (Internet Small Computer System Interface) protocols, which require specialized hardware to interface with the network traffic. In contrast, DAS and NAS systems use more common protocols like Server Message Block and Network File System that already interface with the rest of your network’s devices.
While SAN protocols allow enhanced performance, rapid scalability, and high availability, their unique nature requires specific hardware and network infrastructure that raise acquisition and maintenance and add initial capital expenditure and ongoing management costs.
As these systems have evolved, the FC offerings have advanced, providing newer options like FCoE (Fibre Channel over Ethernet) and FC-NVMe (Non-Volatile Memory Express over Fibre Channel), which specifically address network performance improvements.
A SAN can support an incredible number of storage devices, all interconnected in the fabric of the network — hundreds or even thousands of disks. An experienced IT team can add many powerful management features like data encryption, storage replication, or deduplication, which can increase network resilience while centralizing data management capabilities.
SAN truly shines in a campus environment. The high-speed Fibre Channel backbone of these storage solutions achieves up to 128 Gbps that powers near-instant access to block-level storage — as long as the fiber network infrastructure is in place and users aren’t spread out beyond five or six miles from the SAN itself. Thus, an institutional campus or a business campus like a national or international headquarters can leverage these high-throughput, low-latency network protocols and see the value in deploying a SAN architecture.
For scenarios that are more dispersed geographically, you can still implement a SAN with iSCSI because of its ability to interface with the more common Ethernet and TCP/IP network technology. Operating on the same network as your internet access, iSCSI data access can still achieve up to 100 Gbps in the right conditions.
Whether an organization uses FC or iSCSI, the benefits of a SAN remain the same — ensuring servers are connected by the fabric of the dedicated network. Whether these are physically centralized in an array or virtualized, the goal is to pool a multitude of storage devices into a seamless pool that is centrally managed and optimized. When properly designed and executed, a SAN enhances that pool of storage’s availability by ensuring every element always has at least two points of connection. No matter what happens within the network, there will always be at least one working path between hosts and storage, ensuring much higher availability than a DAS or NAS could offer.
Is SAN the future of enterprise storage?
SAN technology continues to advance. Virtual SAN (VSAN) is proving that you can more easily add flexibility and scalability to the underlying infrastructure in today’s increasingly converged network environments. By leveraging logical partitions or zoning, VSAN offers advances in performance and security. You can also achieve non-disruptive data migration using these advances – moving storage between platforms without downtime. There’s also opportunity for smarter storage in VSAN using intelligent tiers that move data automatically between different performance-level tiers based on frequency of access or other values-based attributes.
Unified SANs are another advance that increases the flexibility of SAN strategy for complex enterprise environments. While SAN supports block storage instead of object or file storage, new approaches to unified SAN can handle multiple protocols on the same network. Of course, there are sacrifices and tradeoffs in a unified environment, as the block storage FC/iSCSI scheme of the SAN infrastructure is where much of the efficiency and speed is found.
Another advance in SAN technology is the rise of converged network protocols like FCoE, which can reduce the infrastructure costs of maintaining multiple, separate networks for both LAN and SAN alongside each other. However, the end-to-end network device families that provide this protocol are limited and still proving their merit. As FCoE gains vendor support, applications in the real world will begin to reveal whether this protocol can achieve the reliability of traditional Fibre Channel SAN.
Lastly, NVMeoF or FC-NVMe protocols promise the speed of access in DAS devices, the availability and cost benefits of x86 server-based controllers, and the simplicity of existing LAN infrastructure. These “superconverged” systems could present a lower-cost entry point into the SAN storage market without requiring the specialized network knowledge of today’s SAN deployments.
What’s the best alternative to a SAN?
Despite all the benefits of a SAN, there are some disadvantages and considerations. Using a SAN essentially builds an entirely separate network infrastructure for your business, one that requires dedicated cables, switches, and servers. The redundancy and speed of a SAN depend directly on the network infrastructure itself, so you can’t afford to cut corners here. To truly see the benefits of a SAN, you must invest heavily in IT expertise and maintenance, particularly in areas such as zoning configurations, security, and data deduplication/replication.
Furthermore, the major SAN benefits only make sense at a certain scale. The larger and more complex your data environment, the more likely a SAN will make sense. However, for more geographically distributed, agile organizations, it’s difficult to justify a SAN for the volume of data involved. Remote SAN tools are growing, providing better management capabilities, but physical distance is still a factor for most SAN deployments.
The alternative to designing, deploying, and administering your own SAN is to find a partner who does better, faster, for less.
Panzura provides a cost-effective hybrid-cloud global file system extensible across hundreds of locations. Overcoming latency to deliver a local-feeling file performance, Panzura allows enterprises to consolidate data using public, private, or dark cloud S3 object storage as a globally available data center.
Storing data in an immutable form with read-only snapshots, Panzura CloudFS makes data impervious to ransomware. Changed data is stored as new data blocks instead of overwriting existing ones.
Using one authoritative data set, Panzura enables multiple locations to operate as if they’re under the same roof. Enjoy local-feeling file performance, automatic global file locking, and immediate global data consistency.
Panzura’s global file system ingests unstructured data, allowing users to monitor all file system activity from Data Services, one central, easy-to-read dashboard. Any user can track the location of sensitive stored data and mitigate potential security risks like insider threats, malware, or ransomware.
It’s paramount that files are available whenever and wherever.
Redundancy within an IT stack is as risk-laden as ever — even the giant public cloud storage providers can experience outages. Infrequent though they may be, their disruptive nature can prove costly.
With its effective CloudFS cloud mirroring, Panzura places overlapping data sets in two separate object stores, giving you data redundancy and high availability. If your primary cloud goes down, CloudFS switches to your secondary cloud store with no interruption and no data loss, letting business continue as usual.
Data is a modern organization's greatest asset. Forward-thinking leadership understands the impact it can have on their strategy and ability to make better decisions. Gaining a competitive edge or achieving ambitious goals depends on the ability to intelligently manage, find, audit, analyze and work with reliable data quickly, easily, and efficiently.
Panzura CloudFS transforms complex, multi-component, and often multi-vendor environments into a simplified data management solution while addressing cost reduction, risk mitigation, and operational complexity — in other words, it offers a real alternative to the SAN.