SANs in 2000 vs. LANs in 1980

Storage-area networks are all the rage today in the storage world. Bringing benefits such as high availability and centralized management to large amounts of data, they address many of the issues critical to today's information needs. They leverage the benefits of advanced networking technologies and merge the worlds of storage and networking. Many companies are moving firmly down the SAN path, implementing successful SANs and beginning to migrate their high-availability production data to the SAN.

As with any other enterprise network, IT managers are going to have to manage SANs. But several questions remain. Is SAN technology ready for prime time? Is there interoperability? Is there management software? Is the organization ready?

Interestingly, these are the same questions we dealt with in the 1980s relative to another new technology at that time: LANs. Here are some similarities between the situation of SANs today and LANs of yesterday:

Diverse network technologies

Looking back on LANs, there was a good deal of uncertainty about what technology would be the standard. As hard as it is to believe now, Ethernet was not always the clear favorite. Some out there may remember (or still be running) Token Ring or other transport technology. And before TCP/IP was crowned king by the advent of the Internet, IPX, Banyan Vines, and other protocols were widely utilized.

With SANs, we wonder whether Gigabit Ethernet or Fibre Channel will become the standard for data connectivity. Some of this may be determined by manageability. Many Fibre Channel products don't yet support IP, but they can eventually borrow from the management tools already developed for LANs. Migration of these tools should not be difficult. On the other hand, Gigabit Ethernet, as a storage connectivity option, already includes highly developed management capabilities.

Diverse network devices

Another similarity between SANs today and early LANs is in the development of devices. Early LAN devices included mostly hubs, routers and bridges. Switches were highly specialized and therefore expensive options, reserved for only the most critical areas. Routers and bridges eventually collapsed into combined devices, and the cost of hubs and switches declined to become almost even at the lowest end.

Initial SAN technology included Fibre Channel Arbitrated Loop (FC-AL) and evolved into more advanced switched fabric. As SANs continue to evolve, there will be convergence of these early devices, allowing a single device to provide both loop and switch capability.

Limited interoperability

Also in the early stages of LANs, device interoperability was 'mostly there.' But to be safe, most people selected either a single vendor or a set of vendors that had partnered and ensured interoperability. Later devices were more 'plug and play,' although even today you will find that most people recognize the advantage of sourcing from one vendor, if for no other reason than to ease configuration and management. There are still no LAN management software packages that provide the full range of configuration and management capabilities for all network devices.

SAN devices will likely follow a similar evolution, where devices will evolve and merge, cost differentials will become less of an issue, and while interoperability will improve to the point of 'anything to anything', there will still be reasons to select from as few vendors as possible.

Plentiful vendors

On the vendor side the similarities may be even more striking. LAN hardware vendors merged and combined in every way imaginable, until we are left with the relatively few market leaders of today. Network management software vendors followed the same course. Yet new vendors continue to emerge and introduce technology advances, which when validated by the market, are then swept up by the same leaders that are introducing advances of their own.

The SAN market will likely follow a similar course - so, when choosing among vendors, a degree of 'reading the tea leaves' should be used to ensure that the vendors you select are more likely to combine with each other than to be combined with a vendor you left out.

One difference between SANs and LANs has more of an effect on the politics than the technology. When LANs were young and people were checking them out, they were looking for file and print services. If the LAN was down, there was always sneakernet. People had not yet begun to rely on network availability. Today, the expectations for high availability are already there. Since the focus of the SAN is to make information available to the corporate network, expectations are high. Without access to the information, the network is irrelevant, so the availability requirements and visibility of SANs today are extremely high. This makes the move to SANs a challenging one - with much greater risk.

With similar issues of connectivity, interoperability, and management, SANs mirror the LAN evolution in many ways. And with significant potential impact on the enterprise, they may also mirror the LAN revolution. In 20 years, SANs may be as prevalent and key to the infrastructure as LANs are today. And as with LANs in the early days, there is still the political/organizational question: Who will have responsibility for them?

Barb Goldworm is an independent consultant with over twenty years experience in the computer industry, with products targeting the enterprise, service provider and end-user markets. Barb has held various technical, marketing, industry analyst and senior management positions with Novell, IBM, StorageTek and several successful startup ventures. She has had responsbility for both the Network and Systems Management and Storage in the Enterprise Newsletters for NetworkWorld Fusion. Barb has been a frequent speaker at industry conferences worldwide for over ten years, and was also the creator and track chair for the Networld+Interop track on Networked Storage. Barb can be reached at barbgoldworm@earthlink.net.

For information on SAN drivers and user issues, see Enterprise Management Associates' latest study on SANs

Tech Insider: SANS
Network World, 06/12/00.

SANs get an optical angle
Network World, 06/12/00.

Newsletter: SANs show progress
Network World, 05/31/00.

Research: Storage-area networks
Network World Fusion

Archive of Network World on Storage in the Enterprise newsletters