What is a storage server?

A storage server is not a general-purpose server. Some view it as a standard server with added storage features, others define it as a purpose-specific "appliance," while some argue the term should exclusively refer to NAS (Network Attached Storage) devices.

This article aims to establish a precise definition of storage servers, distinguishing them from general servers, and provides real-world examples.

General Servers vs. Storage Servers
A typical server is configured to handle multiple roles—such as a file server, print server, application database server, or web server—often combining several functions. Thus, it requires high-speed processors, substantial RAM, and sufficient internal disk space to adapt to dynamic user demands.

In contrast, storage servers are purpose-built. They may have minimal additional storage or massive capacity, depending on their design goals.

Hardware Configuration Differences
"A general-purpose server typically has fewer than five internal disks, whereas a storage server starts with at least six disks, often scaling to 12 or 24 internal disks," explains Graham Lovell, Senior Director of x64 Servers at Sun Microsystems.

Physical Design Characteristics
Storage servers are often standalone units, sometimes designed as 4U rack-mounted chassis. Alternatively, they may consist of two enclosures: a storage unit paired with a nearby server, both mountable in parallel within a rack.

Functional Distinctions
Beyond additional disks, storage servers typically include:

• Embedded storage management software

• Specialized hardware for high flexibility

• Multiple RAID configuration options

• Extra network ports to support concurrent access from more end-users