What is a storage filer?

Types of storage filers: NAS vs. SAN

Storage filers might also be referred to as storage file servers, whether or not they're specific to high-volume workloads. They come in many forms and sizes, including NAS filers and SAN filers.

One key difference between NAS and SAN is that NAS is a standalone storage device with a large data storage capacity. It provides file-based data storage and user-friendly file sharing and is cost-effective, making it suitable for small networks -- e.g., in homes and in small business setups -- and for users with less technical knowledge.

In contrast, SANs are engineered to connect multiple storage devices to a dedicated network, typically based on Fibre Channel or Internet Small Computer System Interface. This network is isolated from the main local area network (LAN) to prevent interference with regular traffic and thus improve performance and data availability. SAN setup is complex, and it is a more expensive type of storage filer than NAS. So, it is more suitable for larger networks in enterprises and other larger organizations.

NAS systems also have high latency and slower throughput, which can be significant problems for enterprises and data-intensive applications -- e.g., video streaming -- although not typically issues for less data-intensive applications.

Another difference between these two types of storage filers is that NAS operates at the file level, while SAN operates at the block level. This means that NAS can access file-level data, which is useful in environments where users frequently collaborate or share files. In contrast, SANs enable servers to directly access storage blocks, which minimizes latency and enables high-speed access. Also, storage controllers can be added to further speed up shared access and minimize latency. These can be substantial advantages for data-intensive tasks where fast data retrieval and high throughput are paramount, such as virtualization and database management systems.

Storage devices can easily be added to SANs to further expand the available storage capacity. This is an important benefit for organizations with growing data volumes and, therefore, growing storage needs. Furthermore, SANs ensure data integrity and availability through redundancy and fault tolerance mechanisms.

Such mechanisms are typically not available in NAS systems, so a NAS system may have a single point of failure that can cause it to go down. Another drawback of these storage filers is that they are not easily scalable. While they can be expanded by adding more drives, lower-end NAS devices offer limited scalability.

Key features of storage filers

The leading storage filers are characterized by the following features and capabilities:

• Around-the-clock availability.
• Scalability and expandability.
• Independent programming.
• Ease of management.
• Support for multiple network protocols.
• High storage capacity.
• Storage redundancy.
• High throughput.
• Security features.
• Connectivity to a variety of backup device types and configurations.

The costs of on-premises storage filers can range from a few thousand dollars to several hundred thousand dollars, although many organizations are now opting for consumption-based, pay-as-you-go services -- metered services -- whether on-premises or in the cloud. Most vendors don't publish the prices of their storage filers on their websites and require organizations to contact them directly for quotes.

Some vendors also provide limited-time free trials that enable companies to evaluate the features and functionality of the vendor's storage filer without having to make an upfront purchase commitment.

The evolution of storage filers

In the early days of shared storage systems, NetApp -- then called Network Appliance -- offered NetApp Filer, a file server appliance that eliminated the overhead traditionally associated with competing storage products. Those early systems should not be confused with today's NetApp products, which are far more advanced than their original filers and often support both file and block storage in the same device.

As of April 2025, NetApp's two main product lines are the All Flash FAS A-Series and the Fabric-Attached Storage storage arrays. A-Series systems are enterprise-class, scale-out all-flash storage devices with advanced data management and cloud integration capabilities. FAS is a family of hybrid flash storage arrays designed for use cases like general-purpose business applications, cybervault workflows, data backup and data retention.

The concept of a storage filer is no longer limited to traditional on-premises systems. Panzura, for example, offers CloudFS, a cloud-native product that can reduce storage volumes and minimize data storage -- NAS and Windows file shares -- silos. CloudFS consolidates file data into public or private cloud storage to help organizations reduce latency, protect data against ransomware, and improve data archiving and disaster recovery.

In recent years, Linux-based virtual storage filers have emerged. One example is SoftNAS from Buurst. SoftNAS is a Linux-based virtual NAS appliance that runs as a virtual machine. This hybrid cloud data integration product combines a software-defined NAS virtual storage appliance, data backups and data integration/replication, making it suitable for high-performance needs and business-critical data.

Like SoftNAS, Ctera's data platform is a hybrid cloud platform. It offers cyber-resilient enterprise file services from the edge to core to the cloud. Key features of the platform include the following:

• Multi-cloud file system with edge acceleration.
• Built-in protection from zero-day ransomware and malware.
• Data sovereignty controls.
• Multiple large language model AI data services.

The storage filer concept has also worked its way to the edge. Microsoft offers Azure FXT Edge Filer, a hybrid storage caching appliance that provides fast file access for high-performance computing (HPC) tasks and read-heavy file access workflows. Azure FXT Edge Filer works with multiple data sources, and multiple FXT Edge Filer hardware devices can be combined as a clustered file system to provide the cache.

Currently, vendors tend to shy away from the term storage filer, although they continue to use filer in various ways. They're also opting for broader descriptors, such as scale-out NAS, but conceptually, the idea remains the same: to centralize file services in support of data sharing across Ethernet LANs, SANs or the internet and often extending these services to cloud platforms or edge environments.

Today's storage filers

The concept of a storage filer has evolved over the years to include a wide range of products, although vendors continue to sell products that conform to a more traditional concept of a storage filer.

For example, Dell offers a variety of PowerScale NAS systems that can serve as storage filers. PowerScale is a family of highly flexible, secure and scale-out NAS systems for many kinds of data-intensive workloads. Dell claims that the PowerScale devices can speed up data ingestion by up to 220% and data retrieval by up to 99%. The devices also lower storage footprint by up to 50%, according to Dell.

The PowerScale systems offer raw node capacity ranging from 3.84 terabytes to 737 TB. In addition, raw cluster capacity varies from 11 TB for the lower-end NAS (PowerScale F200) to up to 737 petabytes for the highest-end NAS (PowerScale F910). All the PowerScale devices support inline data reduction and provide at least 48 GB of error correction code memory per node.

PowerScale NAS systems are suitable for many workloads, including the following:

• AI and generative AI.
• Life sciences and healthcare workloads requiring high capacity.
• High-concurrency workloads.
• Electronic design automation workloads.
• Massive HPC workloads.
• Edge and small deployments.

Maximize the performance of your rackmount NAS appliance by effectively establishing admin accounts, managing permissions and configuring network access. Conduct a thorough diagnostic check, and fine-tune the advanced settings to ensure optimal operation by using our step-by-step configuration guide for how to set up a NAS.