On the Edge of a Blade

On the Edge of a Blade SAN vendors are enlisting in the blade server revolution

July 28, 2004

5 Min Read
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Blade computing looks like the future of data networks, and storage networking vendors want in. After all, the concept underlying blade servers creating a pool of server processing – dovetails with the storage pools created by SANs.

But putting the two concepts together in the real world is tricky – a double-edged blade, if you will. While blade servers have the potential to save enormously on data center costs, it doesn't follow that putting every item in the SAN on a blade will save money. Indeed, without the right design, interconnecting SANs and blade servers could end up costing customers and vendors alike more than the solution is worth.

So what works, and what doesn't? To get the skinny on how blade servers and SANs can make a winning team, we took an unscientific poll of industry sources. Here is a sampling of the feedback we got on how the leading SAN components are making the blade scene:

  • Fibre Channel switches: These are extremely blade-able; at least one vendor, Brocade Communications Systems Inc. (Nasdaq: BRCD), puts the potential market for Fibre Channel switch blades at over $150 million by 2006 (see Brocade Outlines Market Plans).

    While Brocade is OEMing a switch for an IBM blade (see Brocade Outlines Market Plans), and word has it Brocade could supply Hewlett-Packard Co. (NYSE: HPQ) as well, first mover status goes to QLogic Corp. (Nasdaq: QLGC), which has OEM'd its Fibre Channel switch not only to IBM but to Intel Corp. (Nasdaq: INTC), and, if scuttlebutt is right, should win with HP as well. (Apparently, HP is determined to hedge its bets by enlisting more than one switch module approach.)

    The advantage of adding SAN access to remote blade servers is to get any kind of storage off the server proper. To do this effectively, servers need to boot up from the SAN, via special links in the server operating system. Qlogic claims to have this "boot from SAN" capability today, but marketing VP Frank Berry says the vendor is working with Linux and Microsoft OSs to ensure it is sufficiently "rock solid" to inspire blade server customers to eliminate all local disk storage.

  • SAN controllers: Several vendors are looking at how best to put SAN controllers into blade servers, which would reduce the amount of local disk storage a blade server requires and allow the blades in the chassis to access different kinds of outside storage devices, including JBOD arrays – all the while reducing cabling, provisioning, and other costs.

    A main issue is how to ensure there's sufficient throughput between the controller and the blades in the chassis. While proprietary designs are proffered, there's also talk of using InfiniBand as a possible solution.

    Among the vendors looking into putting storage controllers in blades are Egenera Inc. and Xiotech Corp. Vendors such as Maranti Networks Inc. and MaXXan Systems Inc. are also reportedly eyeing ways to combine a SAN switch and controller in blade form. The switch intelligence and virtualization touted by these last mentioned newcomers adds to the possibilities.

  • HBAs: Fibre Channel host bus adapters are included on blade server modules from Egenera, HP, IBM, Intel, and RLX Technologies Inc. – all supplied by Qlogic. But other vendors, including Emulex Corp. (NYSE: ELX), also have offerings in this space. The small adapters fit onto server cards and are often known as mezzanine HBAs, since they create a layer of networking between the servers.

    As with other kinds of storage networking blade server elements, the issue with mezzanine HBAs is throughput. Suppliers are struggling with how to provide sufficient I/O connections between servers and the SAN fabric without taxing the blade chassis's backplane. So far, proprietary answers to the problem seem to rule.

These developments are the tip of an iceberg. Many more possibilities proliferate. Besides Fibre Channel, Ethernet and iSCSI links to storage are in the concept stages. Also, if switches can fit on blades, it's likely the features that fit on those switches could also be shrunk to size as well. As an example, one analyst suggests a blade-able candidate might be IBM's SAN Volume Controller for the MDS 9000 from Cisco Systems Inc. (Nasdaq: CSCO), announced last year (see Cisco & IBM Serve Virtual Combo).Not everything imaginable will make sense from either the customer or the supplier's standpoint, however. One source says, for instance, that the initial cost of blade server gear can exceed pricing for external solutions. That said, the savings over time will likely make up the difference – unless an organization doesn't have sufficient internal demand to make a blade product worthwhile.

From the supplier standpoint, there are a slew of issues. At what point, for instance, will a vendor's selling a Fibre Channel switch-on-a-blade start to cannibalize sales of its external boxes? Ditto the SAN supplier looking to put an HBA or controller in blade form. And what about partnerships? Can vendors navigate the blade world with alliances as successfully as they do today, especially given the added participation of the blade server vendor?

A lot of this must play out in the market, for better or worse. As with any other segment, there will be false starts and failures. But the possibilities for success have at least a handful of storage players, including those mentioned above, ready to try for a grip on that double-edged blade.

— Mary Jander, Site Editor, Byte and Switch

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