As anyone managing business data knows, your storage architecture carries big consequences for performance, scalability and TCO. With data volumes skyrocketing across industries, selecting optimal storage infrastructure is crucial. So what are the main options, and how do they compare?
This comprehensive guide will equip you to make sense of the NAS vs SAN decision by exploring the key distinctions every IT leader should understand. Whether you manage a small business or enterprise data center, you’ll discover which approach makes most sense for your environment and workloads.
We’ll unpack the component layers, protocols and use cases for both Network Attached Storage (NAS) and Storage Area Networks (SAN). With all factors weighed up, you can architect a high-performing storage foundation tailored to your needs and budget.
Demystifying the Main Enterprise Storage Contenders
Before weighing up the NAS versus SAN decision, let’s quickly demystify what each solution entails:
NAS (Network Attached Storage) – A standalone, appliance-like file server designed for data storage and file-based access over IP networks. NAS systems contain their own operating system, CPU, memory and disk capacity in a convenient self-contained unit. Users access shared files over standard networking protocols like SMB/CIFS and NFS.
SAN (Storage Area Network) – A dedicated high-speed storage infrastructure optimized for block-level data access. Rather than a single device, SAN refers to an interconnected network of storage resources sharing a pool of storage capacity over a high-speed Fibre Channel fabric. This dedicated SAN environment serves up storage to connected servers as direct-attached drives for consolidated management.
So in short, NAS provides file-based storage attached to your existing IP network fabric, while SAN introduces a separate dedicated storage network for block-level volumes. Those are the birds-eye differences – let‘s now dive deeper across six key areas:
1. Architecture: Direct-Attached vs Network-Based
The core architecture differs significantly between NAS and SAN for how storage resources connect to client servers:
NAS utilizes your existing TCP/IP LAN, with storage devices directly attached and accessible over file sharing protocols. This networked appliance model allows simple connectivity and centralized pools without major network changes.
SAN however constructs a dedicated storage infrastructure separate from your production IP networks. This specialized Fibre Channel fabric connects high-performance storage arrays to servers for block-level access. While more complex, performance and scalability increases through this dedicated approach.
For small environments, NAS simplifies deployment of shared storage, while still benefiting from centralized administration and capacity. Larger deployments may favor the dedicated SAN concept for higher performance and seamless scaling.
Let‘s explore other key factors influencing which architecture works best…
2. Access Method: File vs Block
Besides architectural style, the protocol used for storage access marks a fundamental difference between NAS and SAN:
NAS systems utilize file-based protocols like SMB/CFIS (for Windows clients) and NFS (for Linux/UNIX) to provide shared folders and file systems to connected users, mimicking traditional on-premises servers.
Contrast this to SAN, which appear at the block level. The consolidated storage pool served over Fibre Channel presents raw volumes to connected servers instead of shares. This facilitates faster access more akin to direct-attached drives. Communication occurs between servers and storage via SCSI commands.
So while NAS focus on file transfers using common networking protocols, SAN skirt the overhead of file-based access, reading and writing block storage for superior performance.
This fundamental difference has implications for application compatibility, speed, and implementation complexity…
3. Performance: Files vs Fibre Channel
Given the different access methods used, relative performance profiles contrast significantly:
NAS ultimately depend on your existing LAN infrastructure. Traffic to and from the NAS shares data links with all other network activity, so available throughput will throttle performance under load. Peak speeds also vary by network type – 1GbE vs 10GbE vs 40GbE in Ethernet environments.
SAN however operate over isolated Fibre Channel fabrics, purpose-built for lowest latency storage traffic. By shifting HDDs and SSDs onto a dedicated high-speed network, storage I/O is no longer Fighting for bandwidth, reducing contention. Throughputs easily reach into multiple Gb/s.
So your workflow needs dictate priority here. Typical NAS speeds should suffice for everyday business files, user directories and backups. But more latency-sensitive workloads will benefit from SAN and Fibre Channel if uptime and speed are paramount.
As for simplicity, NAS wins out. Training is rarely needed to introduce basic NAS shares, while configuring Fibre Channel SAN lies firmly in IT admin territory, given the in-depth skills required.
4. Scalability: Adding IP Addresses vs Seamless Growth
With storage demands growing 50% annually, no modern architecture can ignore expansion. Both models allow additional storage provisioning, but the process and impact differs:
To add capacity to a NAS environment, new physical appliances are added as needed. This simplifies deployment, yet forces spanning workloads across boxes. More critically, introducing another NAS device assigns new IP addresses and/or subnets if maxing out the original range – risking added network complexity.
SAN however present a far more seamless growth model, achieved through storage virtualization. Additional disk shelves connect behind the scenes without affecting the logical volumes exposed to production servers. Both performance and capacity scale almost infinitely this way. Only the storage fabric needs occasional capacity boosts.
Therefore SMBs can easily scale NAS storage as budget allows. Larger organizations where uptime is critical will prefer the near limitless behind-the-scenes expansion possible through enterprise SAN.
5. Complexity: Easy Shares vs Challenging Admin
Given the simpler architecture based on mainstream network technology, NAS solutions earn reputations for device simplicity – often requiring no specialized storage skills to deploy or manage basic functionality.
SAN administration requires far greater expertise, including host provisioning, fabric/VLAN configuration, virtualization management and disk arrays control. While offering richer capabilities, mastering enterprise SAN platforms remains the reserve of storage specialists and certified admins given the skill level demanded.
For technology leaders without dedicated storage teams on hand, a NAS deployment allows shared storage capabilities without the same admin overheads. One-person IT teams are likely better served implementing NAS solutions unless business needs demand SAN performance and scalability today.
6. Cost Considerations: TCO Tradeoffs
For smaller networked storage needs, NAS often wins out based on lower capital expenditure, but for larger deployments the equation changes. Let‘s break this down:
While offering consolidation of direct-attached storage, NAS appliances themselves aren‘t free – with enterprise-class devices ranging anywhere from $1,000 to $50,000+ before disks. Incremental storage adds ~$700 per 8TB HDD, or $1200+ per 1TB SSD.
SAN demands greater upfront investment – minimally requiring Fibre Channel switches (~$7000+) and HBAs (~$1000) per connected server, plus shared disk enclosures (~$25,000+) to hold the consolidated storage. However TB-for-TB costs end lower thanks to higher disk utilization in virtualized pools.
Administration costs must be factored in too however. NAS solutions rarely demand dedicated personnel, with most ongoing management handled working hours alongside other responsibilities.
SAN environments however hungrily consume admin time given routine tasks like performance monitoring, capacity planning, firmware updates, not to mention major version upgrades. Staff overheads quickly outweigh hardware savings.
Total Cost Comparison
Let‘s see cumulative 5 year TCO for a hypothetical 100TB of raw NAS or SAN storage to see all factors balanced:
While your scenario will differ based on workloads and staffing, key considerations emerge:
For smaller storage needs of sub-100TB, NAS often carries lower hardware and human resourcing costs. However for larger consolidated capacity, SAN delivers lower TB-for-TB costs, if specialist resources exist to support the infrastructure.
Choose storage wisely based on all elements of expenditure – acquisition, expansion, maintenance and operation.
Adoption Trends: SAN for Large Enterprises, NAS Preferred by SMB
Industry analysts provide further clues to optimal deployment environments based on real-world adoption trends:
SMB NAS Proliferation – 90% of organizations under 1000 employees utilize NAS for primary storage according to ESG Research – thanks to lower TCO.
Enterprise SAN Preference – Among firms managing over 1 Petabyte of data, IDC finds 8 in 10 opt for SAN thanks to scalability and performance.
Storage historian Thomas Weybrew summarizes the findings: “When evaluating NAS vs SAN, larger datasets and lower latencies steered enterprises to adopt SAN broadly in the 2000s. Yet NAS solutions continue gaining favour across SMBs who value simple deployment and administration.”
For rapidly-growing firms starting with NAS, a build-vs-buy tipping point emerges whereby internal IT resources become overwhelmed, driving pursuit of managed SAN storage services instead.
So scale, skillsets and performance targets all influence the optimal NAS vs SAN deployment decision.
Architecting Optimal Storage for Your Workloads
With the full technology picture in view, where should your NAS vs SAN investments focus? No single architecture reigns supreme across every usage scenario.
For smaller general file serving among 10s of users, NAS often provides the easiest route to centralized storage. Solutions like Synology NAS start below $1000, serving multi-protocol file shares via Gigabit Ethernet to users across Windows, macOS and Linux desktops and laptops. Supporting everyday office documents, libraries, backups and user directories, modern NAS deliver radical simplicity compared to traditional file servers.
If consolidating 100s of Terabytes for 1000s of concurrent users, typically a Fibre Channel SAN becomes the only way to cost-effectively scale while meeting response time SLAs for random IOPs across block-based SQL Server instances or server VM farms. Engineer such environments properly however and costs run into six figures.
Of course hybrid models deploy both file-based and block-based tiers side-by-side to derive specific benefits while mitigating limitations through careful segmentation. Many NAS now also integrate iSCSI block access for flexibility.
Choose wisely based on your individual performance, capacity, scalability and TCO goals. And most importantly, thoroughly analyze working set workloads and growth projections before any purchase. Even the mightiest SAN gets swamped if underspec’d relative to actual machine and user population ramps.
Well-architected shared storage empowers organizations to capitalize on surging data opportunities. We trust mapping the critical NAS vs SAN decision points proves helpful towards building an optimized, robust and cost-effective storage foundation ready for the demands of the 2020s and beyond!
