The ideal of centrally managed storage is not new; it's been around since the days of the mainframe. What is new and exciting is that centrally managed storage is blending with the distributed-network computing paradigm. The result is the new, and often overhyped, Storage Area Networks (SANs) marketplace.

What is a Storage Area Network? In a nutshell, SANs are networking platforms that use high-speed-usually gigabaud-connectivity to interconnect independent storage systems with servers.

Why would you want to build a SAN or consider an outsourced SAN arrangement? In a word, data. Our move from an industrialized economy to the brave new world of information brings with it gobs and gobs of data.

There are several key factors that are significantly driving up the amount of data. First, and probably most obvious, is electronic commerce. As more and more transactions are completed online versus on paper, more and more data is being produced. Likewise, data stores that companies have traditionally held (and not leveraged) are now being transformed and used as part of business intelligence strategies. This is unearthing even more data. Add to this the expansion of data around the globe. And our new interconnectedness is also producing more data. Finally, the need to communicate data ever faster is driving the need for more modular data sets, which also causes us to produce more and more data.

Aside from data, there are a few other factors in play. One is that the data we've been steadily increasing over the past few years has really pushed to its limits the Small Computer System Interface (SCSI) bus that supports server-based storage. In addition, the server-based back-up and restore operations of storage consume heavy amounts of bandwidth. This can impact end-user application speeds or necessitate downtime for maintenance. SANs can alleviate these problems.

Biz benefits

SANs offer some good benefits for companies large and small (and everyone in between, too). By moving to independent storage and gigabaud transfer rates, many of the constraints of server-based storage can be eliminated. Instead of having an abundance of storage on one server and not enough on another, a SAN lets you more efficiently allocate storage to servers based upon need. And, some SANs can interoperate with most any server platform, which makes them attractive in mixed-platform environments.

Bandwidth utilization is also used more efficiently in a SAN setting. Backup applications are usually one of the forces that drive companies to implement a SAN. Instead of backing up data on the LAN and impacting bandwidth, you can perform the back-up (real-time or scheduled) from the SAN without affecting end-user performance.

Aside from bandwidth issues, SANs are also helpful because they let you add and remove storage on the fly without server downtime. This is good because it allows you to maintain a scalable data environment over time and it enables easier diagnosis and repair of storage systems. And, SANs help you increase uptime and fault tolerance as well as improving data integration between dissimilar platforms. Over time, SANs will decrease the overall cost of data storage at your company.

Time for sans?

Do you remember how I mentioned that SANs are overhyped? I said it because SANs, in and of themselves, will not reach their full potential for customers until the rest of the technology catches up. It matters not what the SAN vendors promise you today. Today, the majority of our server operating systems-file systems, systems-management software, and other applications-are not architected to work with the independent pooled storage facilities found in SAN solutions.

According to GartnerGroup, this situation should change, and our operating systems, software, and applications should be ready to interoperate with SANs late in the year 2003. Software and operating-system providers need time to incorporate support for things like physical and logical partitioning of data, better tools to manage database clusters in SAN environments, and enhancements to fail-over strategies.

Beyond software and operating systems, SANs gigabaud connectivity options need to ripen too. Significant work has already been done to support bridging technology to link SCSI devices with Fiber Channel SANs. And pure-play Fiber Channel support is leading the connectivity side of the SANs picture at present.

Industry research also shows that Gigabit Ethernet vendors may also make a play for the SANs market. Gigabit Ethernet players have a good chance of being able to match Fiber Channel support for connectivity of SANs, though there are some differences between the two.

Biz apps

Earlier, I mentioned using SANs for performing LAN-less (server-less) backup operations. This is a key application that draws companies into the SANs fold. But other attractive options might lead you to consider a SAN. For example, SANs technology enables centralized administration of distributed storage resources. This presents a significant savings opportunity for businesses that have storage needs at multiple locations.

Another appealing aspect of SANs is that they can support the storage needs of heterogeneous-platform environments. Not all SANs solutions today have reached this objective, though, since some are still platform specific. Veritas and EMC are examples of two vendors that already support mixed platforms. Support for multiplatform environments is important because you'll be able to manage any-server-to-any-storage configurations that can host applications, data, or file systems of any kind.

Data management also becomes easier in a SANs environment. You can perform high-speed replication functions much faster than in a server-based storage environment.

What's more, you can share data between dissimilar systems. SANs vendors support data sharing at different levels, though. Some solutions allow any platform to access the data, but only the owner to modify it. Other SANs solutions allow mixed platform access and singular access to modification of the data by using a locking mechanism to prevent overwriting. And, others enable concurrent data sharing where multiple reads and writes occur.

Storage can also be managed more efficiently in a SANs environment. Non-removable and removable media can be statically or dynamically allocated depending on what your SANs solution supports.

Now and later

In the mid-to-long term, SANs are the way to go. And, there are solutions that meet the budget of almost any business. However, I'd recommend exploring SANs now with the idea of considering an investment in the technology some time down the road.

Suppliers of server operating systems, system management software, file systems, and applications need time to update their solutions with SANs in mind. And, the jury is still out on whether Fiber Channel, Gigabit Ethernet, or some other standard will lead the SAN marketplace as a transport mechanism over the long haul.

Whatever SAN solution or service you choose, be sure that platform, application, data, and transport interoperability are fully supported. This is an ideal time to test-drive some potential solutions or service-based offerings while keeping your finger on where the market is going.

Maggie Biggs maggie@biggs.com is director of the InfoWorld Test Center, where she evaluates emerging technologies and writes the Enterprise Toolbox column. She has more than 15 years of business and IT experience in the financial sector.