What is File Storage?
Also known as: NAS
File storage exposes data as a hierarchical filesystem over network protocols like NFS and SMB, commonly delivered via network-attached storage (NAS) appliances for shared access.
File storage is a method of storing and organizing data as a hierarchical filesystem, using directories and files as the fundamental units. It is accessed over a network using standard protocols. The most common protocols are NFS (Network File System, originally developed by Sun Microsystems in 1984, now described in RFC 1813 for NFSv3 and RFC 5661 for NFSv4) and SMB (Server Message Block, also known as CIFS, developed by IBM and later Microsoft, with modern versions documented in the MS-SMB2 and MS-SMB3 specifications). A client operating system mounts a remote file system, making it appear as a local directory. The underlying server manages a file system (often ext4, ZFS, or Btrfs) and translates client protocol requests into local file operations.
How it works: A file-storage client sends protocol-specific commands such as open, read, write, and close over TCP port 2049 (NFS) or port 445 (SMB). The server maintains metadata like permissions, ownership, and access times for each file. Locking mechanisms (e.g., NFSv4 delegation, SMB opportunistic locks) allow multiple clients to share files with some consistency. Network-attached storage (NAS) is a dedicated appliance that provides file-storage services. A NAS device runs a stripped-down operating system and serves files to users on a local network. Unlike block storage, which gives raw volumes to a single host, file storage enables concurrent access from many clients under a unified namespace.
Where it fits in the wider stack: File storage sits above the transport layer and below applications. It is one of the three primary storage types in enterprise IT, alongside block storage (SAN) and object storage. NAS gateways often bridge file and object protocols. File storage is common in home networks, corporate file shares, media production workflows, and virtualization environments (when a shared file system is needed for VM templates or user home directories). It is not ideal for high-performance databases, which benefit from lower-latency block access.
Key facts
- Data is organized as a hierarchy of directories and files with metadata.
- Primary protocols are NFS (port 2049, RFC 1813/5661) and SMB (port 445).
- Network-attached storage (NAS) is a dedicated appliance for file storage.
- Supports concurrent file access from multiple clients with locking.
- Contrasts with block storage (SAN) which exposes raw volumes to one host.
How it works in practice
Related terms
References
More in Storage
Block Storage
Block storage is a storage architecture that presents raw fixed-size chunks (blocks) to a computer, which the operating system partitions and formats before use, commonly used for virtual machine disks and database volumes.
Cold Storage
Cold storage is a low-cost, slow-retrieval data tier for infrequently accessed information, such as backups, archives, or compliance records, with retrieval times ranging from minutes to hours.
Erasure Coding
Erasure coding is a data protection method that splits data into fragments (shards) and adds parity, allowing reconstruction from a subset of fragments; it is commonly used in cloud object storage to tolerate failures efficiently.
Fibre Channel
Fibre Channel is a high-speed networking standard primarily used to connect storage devices in storage area networks, operating as a dedicated protocol stack separate from Ethernet.
Hot Storage
Hot storage is the default high-performance tier in object storage systems, optimized for low-latency access to frequently retrieved data.
iSCSI
iSCSI is a storage protocol that encapsulates SCSI block-level commands over TCP/IP, enabling servers to access remote disks as if they were locally attached.
NFS
NFS (Network File System) is a distributed file system protocol originally developed by Sun Microsystems that allows a client to access files over a network as if they were local. It is widely used in Unix and Linux environments and runs over IP networks.
Object Storage
Object storage is a flat data storage architecture that manages data as immutable objects, each with a unique identifier, metadata, and API access over HTTP. It is the model behind Amazon S3 and similar cloud storage services.
RAID
RAID (Redundant Array of Independent Disks) combines multiple physical disk drives into a single logical unit to improve performance, fault tolerance, or both, using techniques like striping, mirroring, and parity.
RAID 0
A data storage method that splits data across two or more disks in stripes to improve read and write performance, but provides no fault tolerance.