One constant facing IT resellers and integrators is how to provide for ever-expanding storage requirements. In a recent InfoWorld Enterprise Storage Survey, 96 per cent of respondents indicated that their needs will increase this year, and 39 per cent indicated that they could always use more storage capacity. This is no surprise: some of the largest enterprises already maintain data past terabyte levels and are starting to plan for pentabytes and exabytes. Fifteen per cent of the respondents have a terabyte or more online.
To use those mountains of data effectively, you must be able to sling data around your network in chunks of gigabytes and terabytes. The best way to accomplish this, now and in the future, is to use fibre-optic technology as the basis for your storage networking schemes. Whether you're building a SAN (storage area network) or connecting NAS (network-attached storage) devices, a high-fibre diet is the key to your enterprise storage system's longevity, performance, and stability.
Although high-end storage solutions have traditionally used fibre, copper is still widely used in lower-end SCSI products and in quite a few server rooms. This is the first thing that has to change. Fibre is superior to copper in three key areas: the distance data can be transmitted, security, and throughput, which are all particularly advantageous in a storage network.
A superiority complex
First, copper-based storage networks suffer from severe distance limitations, which can be measured in feet. For example, you can't run Fibre Channel (FC) protocols through copper beyond 30 metres, but using fibre optics allows you to spread out more than 1.5km before performance degrades. For this reason alone, we expect that most real-world FC installations will be "fibre-on-fibre".
Second, security becomes important when you start spreading your storage network across a campus. Exposed copper cables provide an excellent radio antenna for broadcasting data without your knowledge. Although tales of data theft via RF (radio frequency) interception seem to be strictly James Bond material, corporate espionage still depends more on defecting employees or overheard conversations than on a black van parked across the street.
Many CTOs require above-normal security for sensitive projects, yet they have no idea who might be listening in on the corporate network. This is even more critical when you're dedicating a network for storage traffic, because your databases may be the object of some teenagers playing this century's version of Capture the Flag.
Finally, the throughput required for higher speeds isn't possible with copper. You can run data at gigabit speeds through copper (if all of the connections are perfect) but with 10Gb standards in sight, copper technology is pretty much maxed out. It's clear that fibre is no longer strictly a backbone technology; it ought to be the medium of choice in the server room and beyond.
When our respondents were asked about their top two storage concerns, speed and performance were cited more than half of the time, at 44 per cent and 10 per cent respectively. Although the fastest network is only as responsive as its slowest device, it is nevertheless in your best interest to require fibre for your storage network.
But much more goes into the mix of enterprise storage networking than running lengths of fibre and hooking it up to a bunch of boxes.
Because unforeseen changes in your company, such as mergers, will upset any long-range commitments you make to a storage environment, it makes sense to plan for flexibility. Finding ways to integrate technologies and leverage the strengths of each is essential to surviving potential storage crises in the future.
Consider also the very real possibility that today's SAN technology may not live up to expectations. Although the theory behind current implementations using Fibre Channel makes sense on paper, it's floundering in execution. For example, interoperability of SAN components from multiple vendors remains elusive. Management tools are still vendor-oriented, and the relative lack of people skilled in the technology increases support costs.
It is very likely that future SANs will use IP-like protocols, although how this is to happen is an unfolding story. Traditional approaches use IP tunneling in which frames of Fibre Channel data are encapsulated in IP packets. Unfortunately, tunneling schemes slow transmission by adding latency and overhead and, essentially, only connect islands of FC-based SANs, instead of providing a truly integrated environment.
Promises for the future
One SAN vendor, Nishan Systems, from the US is breaking the mould by adopting a path that integrates existing SCSI and Fibre Channel protocols with IP.
This approach, called SoIP (Storage over IP), is attractive for many reasons, the foremost being that a lot more employees understand and can support IP than Fibre Channel. Also, companies can use existing LAN, MAN (Metropolitan Area Network), and WAN hardware with Nishan's SoIP-based switches. These boxes, which debuted February 5, aren't cheap - they start at less than $US10,000 - but because a decent SAN project budget starts far beyond that, we'll ignore any instinctive sense of sticker shock.
Nishan has submitted much of the underlying protocol-level technology to the Internet Engineering Task Force (IETF), including a naming service and Fibre Channel-over-IP protocols for local and global use. (An overview is available on the IETF Web site, www.ietf.org/internet-drafts/draft-monia-ips-ifcparch-00.txt or Nishan has a summary on its site www.nishansystems.com).
Several leading storage and system vendors, including ADIC, EMC, Emulex, IBM, Legato, Nortel, Spectra Logic, Sun, and Veritas, announced their support when the draft was submitted last December, which should encourage an early IETF adoption.
How this "SoIP opera" plays out is anyone's guess, but one thing is certain: the hard part for many organisations will be making all the hardware and software work together in a cohesive and coherent way. Nishan's SoIP approach represents a milestone in storage networking by giving customers a way to pool storage devices using widely disparate protocols. But more important, it represents a potential foundation for future storage networks.
One of the keys to business success in the new century is the effective use of data. A growing amount of data will inevitably place more strains on your technology. Taking advantage of an enterprise's information is going to require new approaches to how we network our devices and how we make the physical connections.
No matter what your situation is, your data needs are increasing with every hour. How you manage that growth may determine your business' success or failure.
The Bottom Line
Storage networking ****
Busin-ess Case: Smart companies will spend more time planning their storage networks for flexibility instead of agonising over specifics. Fibre-optic technology is key for ensuring that whatever choice is made remains useful in the future. Finding ways to harness competing technologies will require rethinking how storage networks are designed.
Techn-ology Case: Whether you prefer NAS or SAN, you'll probably have to support both if your company undergoes an acquisition or merger. Making them work together requires either inefficient IP tunneling schemes or integrating storage protocols with IP technology.
Pros:-l Fibre is essential for its superior transport capacityl SoIP promises to connect disparate storage protocolsl Segregating storage devices to an isolated network allows for faster device interfaces without network restructuringCons-:l Many SAN schemes don't interoperate welll -SoIP needs wide standards acceptance to be useful