A storage server is typically less powerful than a standard server, but has more storage space, storage access interfaces and specialized data retrieval and management utilities. A storage server generally serves as a central point of access for data storage and access. Local client nodes and remote computers access the storage server through a GUI control panel and FTP or through programmatic API access by software and applications. It can be used for routine or frequently used data storage and access, or it can serve as a backup server for storing backup data.
A storage server is an integral part of direct attached storage (DAS), network attached storage (NAS) and other storage networking technologies.
HP has five ProLiant models available as general-purpose servers or storage servers/NAS filer — each has the same basic hardware configuration. If licensed as a storage server, the user may not run general-purpose applications on that server. If the same ProLiant server is being used as a regular server, however, applications can be run on it. To sweeten the deal, HP prices its storage servers a little lower than their general-purpose siblings.
NAS, it turns out, isn't really storage networking. Actual network-attached storage would be storage attached to a SAN. NAS, on the other hand, is just a specialized server attached to a local-area network.
In addition, HP's NAS-based storage servers have extra functionality built into the operating system — storage-specific management tools, "quota-ing" features, storage reporting capabilities, and a Web-based user interface that makes it easier to configure file and print. These features are not available on its general-purpose servers.
So is NAS really just a storage server? The answer varies, depending on whom you ask. But it appears there is very little difference between them. NAS, it turns out, isn't really storage networking. Actual network-attached storage would be storage attached to a storage-area network (SAN). NAS, on the other hand, is just a specialized server attached to a local-area network. All it does is make its files available to users and applications connected to that NAS box — much the same as a storage server.
The ProLiant DL585 storage server is one example of a HP NAS gateway.