NAS (Network Attached Storage) and servers are two common types of computing devices used for storing and serving data. While they share some similarities, there are key differences between standalone NAS appliances and traditional servers.
How is NAS different from a server
A NAS is primarily focused on providing file-level data storage and sharing across a network. A server performs more general compute functions like running applications, websites, databases, virtual machines, etc along with storage.
Some key traits of NAS devices:
- Optimized specifically for file storage and sharing
- Operating system dedicated to storage management
- Accessible by multiple client devices over a local network
- Managed through a web or desktop interface
- Offer redundancy through RAID configurations
Some characteristics of servers:
- General computing systems capable of running apps/services
- Run mainstream operating systems like Windows, Linux, etc.
- Accessible by client devices and users over a network
- Support running virtual machines and containers
- Used for web hosting, databases, print/file sharing, etc
While NAS appliances are storage-centric, servers provide multi-purpose computing functionality.
Hardware
The hardware architecture of NAS and servers also differs:
NAS hardware
- Pre-configured, optimized appliances from vendors like QNAP, Synology, Netgear, etc.
- Designed specifically for 24/7 operation and high reliability
- Include redundancy features like dual power supplies, fans, network ports
- Leverage ECC RAM to prevent against data corruption
- Typically contain multiple bays for adding storage drives
- Offer expansion via eSATA, USB ports
- Low-powered ARM or Intel Atom processors
Server hardware
- Built using standard PC/server components
- Configured to suit specific performance requirements
- Components like CPU, RAM, drives customized to workload
- Rackmount, tower, blade or custom form factors
- Include multi-core Xeon or AMD EPYC processors
- High amounts of ECC RAM - 64GB to 1TB+
- Storage connectivity via SATA, SAS, NVMe, SAN
- GPUs added for ML/AI workloads
The fixed NAS appliances optimize for storage while servers provide versatile, customizable compute.
Storage Capacity
There is a vast range of possible storage capacities between NAS CPU and servers:
NAS storage capacity
- Start from as little as 2 bays to over 50 bays in enterprise units
- Typically support both 3.5" and 2.5" HDDs/SSDs
- Individual capacity from 4TB to 16TB per drive currently
- Multiple drive RAID configurations for redundancy
- Total capacities from 10TB to 1PB+ in high-end NAS clusters
- Expansion possible via external JBOD enclosures
Server storage capacity
- Varies greatly based on number and type of drives
- Supports SAS and NVMe drives optimized for performance
- Individual SSD capacities up to 30TB currently
- With 24/7 operation, servers leverage higher MTBF enterprise-grade drives
- SAN-attached servers can utilize almost unlimited external capacity
- Hyperconverged servers combine internal storage and compute
- Specific capacity tailored to application requirements
The intended roles of NAS and servers naturally dictate their storage sizing.
Performance
There are some key performance differences between the two:
NAS performance
- Optimized to provide adequate throughput for multi-client access
- 1GbE to 25GbE or higher network interfaces
- SSD caching improves response times
- RAID enhances read/write speeds
- Auto-tiering places active data on faster drives
- Designed to support typical office workloads
- Throughput speeds from 50-6000 MB/s depending on model
Server performance
-Tailored for maximum throughput and IOPS for hosted apps
- 10GbE to 100GbE networking and RDMA optimized
- NVMe and all-flash arrays deliver ultra low latency
- Response times below 1ms
- High core count CPUs provide immense parallelism
- GPUs process heavy computation e.g. AI
- Performance tuned to application needs
- Throughput from GB/s to TB/s speeds
While both can offer good performance, servers are designed to deliver unhindered speed for apps.
Operating Systems
There are clear distinctions between the operating environments:
NAS operating systems
- Custom embedded OS purpose-built for storage e.g. FreeNAS, Synology DSM, QNAP QTS, Asustor ADM
- Optimized for file sharing protocols - CIFS/SMB, NFS, AFP, FTP
- User-friendly web and desktop admin interfaces
- Support extensive storage management features
- Application support via Docker, VMs, database servers
- Regular OS updates from vendors
Server operating systems
- General purpose server OS - Windows Server, Linux distros, Unix, etc.
- Support running a wide variety of applications and services
- Access via remote desktop, SSH, command line
- Advanced controls for networking, users, security, scripts
- Hypervisors for virtualization - vSphere, Hyper-V, Proxmox, Xen, KVM
- OS tailored to application e.g. Windows for Exchange, AD
The dedicated NAS OS focuses on storage while server OS enables general computing functionality.
Network Protocols
There are some commonalities but also key differences in network protocols:
NAS protocols
- Primary file access via CIFS/SMB, NFS, AFP
- Standards-based protocols for wide compatibility
- Built-in FTP, WebDAV servers for file transfer
- Some offer block protocols like iSCSI for raw volumes
- Accessible over LAN, WAN and Internet
- Secure remote access through VPN or HTTPS
Server protocols
- Anything that enables delivery of hosted apps - DHCP, DNS, HTTP/S, FTP, SMTP, etc
- Networking optimized for high throughput - RDMA, RoCE, iWARP
- Block storage access via iSCSI, FCoE, FC
- Traffic prioritization appropriate for each app
- Secure remote access via SSL VPN, RDP, SSH
While both support standard network protocols, servers are optimized for application traffic flows.
Use Cases
The predominant use cases vary considerably:
Common NAS uses
- File serving and shared storage for offices
- Centralized storage for backups
- Media storage and streaming
- Surveillance recorder for security cameras
- Shared printers and scanner repository
- Git server repository
- Small business database hosting
- Static website hosting
Common server uses
- Application hosting - databases, CRM, ERP, HRMS, etc
- Web hosting - Apache, Nginx, IIS
- Application development environments
- Virtualization with hypervisors
- Server colocation services
- High performance computing clusters
- Big data analytics platforms
- Cloud and edge computing nodes
The usage scenarios naturally align with the strengths of each platform.
Management
There are clear contrasts in how NAS and servers are managed:
NAS management
- User-friendly web UIs or desktop apps for admins
- Centralized monitoring of storage, disks, apps, security
- Storage management features - snapshots, replication, quotas
- Automated tasks like backups to cloud or tape
- Alert notifications via email, SMS
- Mobile apps for remote administration
- Real-time and historical performance graphs
- REST APIs for integration and automation
Server management
- Direct OS access via remote desktop, SSH
- Server software provides management capabilities
- Command line for advanced configuration
- Automation via PowerShell, bash scripting
- Agents for central monitoring tools e.g. Nagios
- APIs integrate with DevOps tools
- Out-of-band management via BMC/IPMI
- Higher technical expertise required
NAS devices emphasize simplified administration versus servers offering advanced controls.
Scalability
Both offer expansive scalability through different approaches:
NAS scalability
- Most support clustering and distributed filesystems
- Combine multiple NAS heads into a cluster for increased capacity, performance and redundancy
- Some support up to over 100 nodes per cluster
- Seamless single namespace for all storage
- Options to scale up storage per node and scale out by adding nodes
- Enterprise NAS deployments can reach exabyte scale
Server scalability
- Scale vertically by adding CPUs, RAM, drives to existing servers
- Scale horizontally by deploying more physical servers
- Hyperconverged and software-defined storage on commodity servers
- Cloud computing provides limitless virtualized servers
- Enterprise SANs enable almost unlimited external storage
- Software optimizations enhance performance at scale
- On-prem object stores scale to exabytes like Ceph and GlusterFS
While both can scale immensely, NAS accomplishes it more seamlessly while servers offer flexible deployment models.
Data Protection
Keeping data safe and resilient is a top priority for both technologies:
NAS data protection
- Redundant components - power, fans, network
- RAID detects and repairs disk failures
- Snapshots capture mutable backups
- Replication copies data to remote NAS
- Cloud backup and sync
- Tiering moves data to external object storage
- Watchdog timers detect system freezes
- UPS keeps system online during power failures
Server data protection
- Clustering detects failures and redistributes load
- SAN replication protects against site disasters
- Array-based snapshots, cloning and replication
- Virtual machine backup and replication
- Agents back up guest VMs and databases
- Cloud data protection products
- Tape libraries for long term archiving
- Mailbox database availability groups
While both provide strong data protection, NAS includes built-in features while servers leverage external products.
Security
Robust security is essential on both platforms:
NAS security features
- File and folder-level permissions - read, write, modify
- Posix ACLs provide user and group access controls
- Create shared folders for different user groups
- Limit users to specific networks or shared folders
- Encryption of storage volumes and folders
- VPN and SSL for secure remote access
- Antivirus software options
- Activity and access auditing
Server security methods
- Trusted Platform Modules (TPM) for hardware root of trust
- OS firewalls, antimalware tools
- Network traffic filtering, inspection and logging
- OS hardening like SELinux and AppArmor
- Encryption of drives and virtual machine files
- Public Key Infrastructure (PKI) manages certificates
- AAA - RADIUS and LDAP integration
- Virtualization to isolate apps and data
- Security technical implementation guides
Both platforms utilize encryption, access controls, traffic monitoring and other security measures appropriate to their roles.
Cost
The total costs differ substantially:
NAS pricing
- Pre-configured appliances starting from $200 to $5000+
- Enterprise all-flash NAS can be $50,000+
- Additional cost for hard drives
- Offload tiers like object storage, tape and cloud
- No license cost for NAS operating system
- Optional extended hardware warranties
- Lower administration, electricity and real estate costs
Server pricing
- Wide range based on hardware performance and features
- Individual servers $500 to $20,000+
- Hyperconverged nodes may be $20,000+ each
- SAN storage arrays start from $10,000+
- Software licensing - Windows Server, VMware, databases, apps
- Higher power, cooling and rack space costs
- Dedicated IT admins for configuration, maintenance and troubleshooting
- Server lifecycle costs wide-ranging
While both carry significant costs, NAS hardware is generally cheaper while servers have licensing and administrative costs.
Questions Related to NAS and Servers
What are the differences between direct attached storage vs NAS?
Direct attached storage like USB or internal drives connect directly to a single computer vs NAS provides shared access for multiple devices over the network. DAS suits single user storage while NAS enables centralized data.
When is SAN used compared to NAS?
SAN provides block storage access directly to servers vs NAS offering file storage sharing across the network. SAN suits high performance needs like databases and virtualization. NAS is popular for office file sharing.
Can servers and NAS be used together?
Yes, it's common to have servers handle mission critical applications while using NAS appliances to provide general purpose file serving and shared storage as a complementary solution.
What kinds of applications can run on a NAS?
Many NAS operating systems allow running web servers, databases, media servers, surveillance management software, backups targets and other apps that don't require high computing performance.
How does a NAS OS differ from a general purpose server OS?
NAS operating systems like Synology DSM, TrueNAS and QNAP QTS are dedicated to storage management and optimized for accessing shared files vs server OS that are made for generalized computing functionality.
What is the difference between a file server and a NAS device?
A file server traditionally refers to a general purpose server running Windows, Linux, etc that shares files and printers. A NAS is an appliance specifically designed from the ground up focused on storage and simpler for organizations without dedicated IT staff.
Conclusion
While NAS appliances and general purpose servers have some overlap, they are tailored for different primary use cases. NAS emphasizes secure file storage and sharing that is easily accessible from multiple client devices over the network. Servers focus on running business applications, websites and services accessed by users along with secondary storage needs.
NAS simplifies storage consolidation while servers power mission-critical workloads and computing services. The distinctions between the two technologies fall along lines of hardware architecture, operating systems, protocols, performance, scalability, security, costs and use cases. For most organizations a mix of dedicated NAS storage and application servers running on general computing infrastructure provides an ideal on-premise IT environment.
