Last Updated: 06-24-2010 , Posted: 02-05-2010
A Guide to help you Understand Storage Networking Technologies.
The phrase storage networking is a general term — most commonly associated with enterprises and data centers — that describes a high-speed network of shared storage devices. A storage network is used by IT departments to connect different types of storage devices with data servers for a larger network of users. As more storage devices are added to the storage network, they too will be accessible from any server in the larger network.
Enterprise Storage Forum has been covering storage networking for more than a decade. In this "Storage Networking: The Basics" featured article, Henry Newman, CTO of Instrumental Inc. and a regular Enterprise Storage Forum contributor, offers an overview of the basics of storage networking technologies being used today.
Storage Networking: The Basics
Modern storage networking has evolved from the mid-1990s, where storage was connected via Fibre Channel hubs using Fibre Channel arbitrated loops (FC-AL), to today, where we have Fibre Channel fabrics, iSCSI over 1GbE or 10GbE, network-attached storage (NAS), InfiniBand and FCoE, which can all be used for storage networking. I believe that over the next few years we are going to see Fibre Channel fade away as a technology in favor of Ethernet.
Storage networking grew out of a new set of requirements for UNIX systems in the 1990s. Back then, storage was still relatively expensive compared to servers, and breaking the storage in a server model (DAS) and allowing a storage pool to be shared with a group of servers was important, as was reliability. So each server then had it own storage that was allocated from a large pool of RAID storage. Some of the developments that allowed this were the development of RAID controllers, and, of course, Fibre Channel.
The obvious next step was sharing data as opposed to sharing storage. This data sharing requirement started to appear in the late 1990s with the introduction of shared file systems from a number of vendors. At first these were developed for specialized application requirements for a small number of servers, but by the middle part of this decade, these file systems become pretty general purpose and could support hundreds of servers, and sharing data today is as common as sharing storage was just five to seven years ago.