Network-attached storage (NAS) servers are dedicated file storage devices that connect to a network, allowing multiple users and devices to access and share data from a centralized location. A key specification of any NAS device is how much storage capacity it offers.
What is a NAS server?
A NAS server is essentially a small computer with its own operating system optimized for file sharing and storage. Unlike a regular desktop computer, a NAS has no keyboard or display. It’s designed to be connected to a wired or wireless network and accessed remotely from other devices on that network.
The primary purpose of a NAS is to provide centralized data storage and backup for all the computers and devices connected to the network. This allows multiple users to access, store, and share files in one common location. NAS devices also typically include built-in RAID functionality to provide redundancy and protect against drive failures.
Key NAS storage specifications
There are several key specifications to consider when looking at the storage capacity of a NAS server:
- Number of drive bays – Most NAS units have space for 2, 4, 5, or more hard drives. More drive bays allow for higher total capacity and storage scalability.
- Supported drive types – NAS devices support 3.5″ and 2.5″ hard disk drives (HDDs) and solid state drives (SSDs). The drive types supported will impact the maximum potential capacity.
- Supported drive capacities – The maximum capacity of individual drives supported will directly affect total NAS capacity. Many NAS devices support high capacity 10TB, 12TB, 14TB or larger HDDs.
- RAID configurations – NAS servers allow configuring multiple hard drives into RAID arrays for performance and redundancy benefits. This impacts usable storage vs raw capacity.
Standard consumer NAS storage capacities
Entry-level consumer NAS devices aimed at home users typically start with 2 or 4 drive bays and support up to 16TB or 32TB of raw storage capacity. Many popular consumer models offer:
- 2 bay NAS – Up to 32TB raw capacity (with 2 x 16TB HDDs)
- 4 bay NAS – Up to 64TB raw capacity (with 4 x 16TB HDDs)
Larger 5 and 6 bay consumer NAS units are also available, supporting up to 80TB or 96TB raw capacity depending on maximum drive sizes supported. Most consumer NAS devices support 3.5″ SATA HDDs up to 16TB per drive.
SMB/SOHO NAS storage capacities
For small and medium businesses (SMBs), NAS systems aimed at office use offer greater storage scalability. Models targeting SMBs and power users typically provide:
- 4 bay NAS – Up to 128TB raw capacity (with 4 x 32TB HDDs)
- 8 bay NAS – Up to 256TB raw capacity (with 8 x 32TB HDDs)
- 12 bay NAS – Up to 384TB raw capacity (with 12 x 32TB HDDs)
Many SMB NAS systems support both 3.5″ HDDs up to 32TB and high performance 2.5″ SSDs for cache or storage tiering. Some also offer expansion units allowing capacity to scale into the petabyte range.
Enterprise NAS storage capacities
At the highest end of the spectrum, enterprise NAS systems are designed for the most demanding business environments. Enterprise-class units offer reliability features like redundant power supplies, networking modules, and storage controllers.
Enterprise NAS offers essentially unlimited storage scalability. Maximum capacities depend on the supported drive types and number of drive bays or expansion units. Some examples of enterprise NAS storage tiers and capacities include:
| NAS Tier | Drive Bays | Drive Capacity | Raw Capacity |
|---|---|---|---|
| Rackmount NAS | 24 bays | 16TB HDD | 384TB |
| Large capacity NAS | 108 bays | 16TB HDD | 1.7PB |
| Mainframe NAS | 360+ bays | 18TB HDD | Over 6PB |
Adding flash drives or SSDs for caching and storage tiering is also common in enterprise NAS to maximize performance.
Main factors impacting NAS storage capacity
To summarize, the primary factors that determine the total storage capacity of a NAS server include:
- Number of drive bays
- Supported drive types (HDD, SSD, etc)
- Maximum drive capacity supported
- RAID configuration
- Ability to expand with external drive enclosures
By combining these factors, both consumer and enterprise NAS models can now provide multiple petabytes of centralized storage on the network.
On the low end, an entry-level 2 bay NAS may provide only 16TB usable RAID storage. Meanwhile, a fully scaled enterprise NAS can exceed 10 petabytes of total capacity. This demonstrates the incredible range and flexibility of NAS solutions on the market.
Common RAID configurations and their impact on usable capacity
One key point to understand is how RAID impacts the usable storage capacity compared to the raw physical drive capacity in a NAS system. Some typical RAID options include:
- RAID 0 – Stripes data across all disks for highest capacity utilization but no redundancy.
- RAID 1 – Mirrors two disks to protect against single disk failure but usable capacity is halved.
- RAID 5 – Stripes data and parity information across three or more disks for redundancy while retaining high usable capacity.
- RAID 6 – Like RAID 5 but provides dual parity for higher fault tolerance and reduced usable capacity compared to RAID 5.
For example, a 4 bay NAS with four 8TB HDDs provides 32TB of raw storage. But in a RAID 5 configuration, 1 disk worth of capacity is used for parity, so usable capacity is reduced to 24TB. RAID impacts both capacity and redundancy, so it’s an important consideration when purchasing a NAS.
Typical capacities based on user type and budget
In summary, the amount of storage a NAS provides can vary tremendously based on the use case. Some typical capacities by user type include:
- Home users – A 2 or 4 bay NAS with up to 32TB capacity for personal photo, video, media servers, and backup.
- Small businesses – An 8 to 12 bay SMB NAS with 64TB to 192TB for shared office file storage, backups, and virtualization.
- Enterprises – Rackmount NAS units scaling from 384TB up to over 10PB total capacity for massive storage consolidation.
Budget also impacts capacity. More affordable NAS units under $500 may offer just 4 or 6TB. High-end enterprise NAS devices can cost over $50,000 and scale up to petabytes of centralized storage.
Choosing the right NAS capacity
Determining appropriate NAS capacity requires estimating your storage needs both now and in the future. Key questions to ask include:
- How much data needs to be stored today?
- How quickly is storage usage growing?
- What is the expected data growth over the next 3-5 years?
- What types of data will be stored (documents, media files, backups, etc)?
- How many users will be accessing the NAS concurrently?
Consider both current needs and likely future growth. It’s always better to have some room to grow rather than running out of space too quickly and having to upgrade or scale out. Also factor in sufficient redundancy via RAID to protect your data.
Increasing NAS capacity over time
Most NAS solutions allow you to increase capacity over time as your storage needs grow. Some options include:
- Add larger drives – Upgrade to higher capacity HDDs or SSDs.
- Expand with additional drives – Use empty drive bays to add more storage.
- Add external drive enclosures – Connect external drive shelves via eSATA, USB, or SAS.
- Scale-out NAS clustering – Combine multiple NAS heads into a single clustered file system.
With their modular drive bay design, NAS devices are one of the most flexible and scalable storage solutions available for home and business use. Capacity can easily be expanded based on your evolving needs.
Conclusion
In summary, NAS server storage capacity can range from as little as 4TB up to over 10PB in high-end enterprise systems. Actual NAS capacity depends on the number of drive bays, types of drives supported, maximum individual drive capacities, RAID configuration, and ability to expand with external storage.
Planning current and future capacity requirements in advance allows selecting the right NAS model to meet your storage needs both now and further down the road. The incredible flexibility of NAS solutions enables scaling up or out as data growth requires.