Making Sense of Storage
Server Attached Storage includes any storage device attached to a file server on a LAN. Price, capacity and fault tolerance have made RAID (Redundant Array of Independent Disks) the leading technology for server-based storage in the 1990s, but RAID arrays grow increasingly expensive to manage as storage needs scale, and there are faster alternatives.
Network Attached Storage solutions separate data from applications by storing data on "filers" instead of application hosting servers. Filers are attached to LANs, not servers, and can share files across multiple applications, platforms and operating systems. However, since filers and servers share the same LAN, network performance can be affected.
Enterprise Storage Networks can offer a 40 percent cost reduction over server-attached storage. They need fewer personnel to manage, and allow backup, restoring and archiving data to be handled more efficiently.
Storage Service Providers are firms that lease storage from their own data centers, or administer their customers' installed storage infrastucture.
Storage Area Networks offer higher speeds and throughput than NAS systems by offloading data traffic to a separate network for storage devices. The downside: SANs have difficulty supporting multiple operating systems and platforms. Users also complain that they are unable to integrate SAN solutions from different vendors.
ISCSI (Internet Small Computer Systems Interface) is a new standard enabling storage and retrieval at speeds of 1 GB/second or higher over TCP/IP networks. While promising, products using this standard are only now emerging and will only be appropriate for companies with IP backbones capable of handling gigabit traffic.