Why blade servers still don't cut it, and how they might
The blade manifesto
Sometimes, a good idea just doesn't take off. OK, this is information technology, not philosophy, so let me rephrase that more accurately.
Sometimes, ideas and habits that were once laudable have an immense inertia that prevents a new and perhaps better idea from building momentum in the market. Such is the case with the wonderful idea of blade servers. But there are times when a standard, however begrudgingly adopted by IT vendors, can overcome that inertia.
Every couple of years, the situation with blade servers boils my blood a little bit, like a squandered opportunity does for most of us. Here we are in 2008, eight years after commercial blade servers first came to market, and I find myself hoping that we are on the cusp of a new wave of innovation that will finally bring the standardization that will make blade architectures the norm, not still the exception, in the data centers and data closets of the world. Hope springs eternal, just like frustration.
What set my blood to warming again about blades recently was a set of projections from the analysts at Gartner, who released a report that said blade servers were the fastest-growing part of the server space, but that the lack of standards and rapid change in the underlying technology inside blade servers are limited the adoption of blade servers.
This is something I have been complaining about since day one in the blade server space - in fact, before Compaq's "QuickBlade" and Hewlett-Packard's "Powerbar" blade servers even came to market. So have other analysts - including those at Gartner - and so have customers. And, because money talks in IT, the blame for the lack of standards can be placed squarely at the feet of end users, who after surviving decades of vendor lock-in for operating systems and servers should know better.
But, in the defense of end users, blade servers came out when the IT market was entering a recession after a big boom, and the data center loading, price/performance, and administrative issues IT departments were facing made us accept non-standard blade equipment rather than forcing vendors to produce better standards.
The same thing happened in the recessions of the late 1980s and early 1990s, which sparked a move from proprietary minis and mainframes to Unix machines with incompatible but standards-based operating systems. Common Unix APIs and functionality were better than no standards at all, and RISC iron was cheaper because of competition, so it was as good as it was going to get. Or, more precisely, it was as good as IT vendors were going to let it get until more customer pressure came to bear.
In the Gartner report, the analysts reminded IT shops of some projections it has made recently. In 2007, Gartner reckons that blade servers represented about 10 per cent of shipments, and between 2007 and 2012 the company expects that blade shipments will grow at a compound annual growth rate of 19 per cent to represent 20 per cent of total server shipments by 2012.
This is not, as many had said back in the dawn of the blade server era in 2000, the same kind of adoption rate seen by rack-mounted servers. Rack servers pretty much took over the data centers of the world because of standardized form factors and density in the span of a few years in the late 1990s, and towers basically persist within small businesses and as departmental machines within larger organizations.
Blades could have had a 50 per cent or higher share of the market years ago, provided there were standards for blade and chassis form factors, inter-connectivity of peripherals like switches, and common and open APIs for blade software management software. And that would have killed profits, so it didn't happen. Not one of the few remaining blade players - who are the brand name rack and tower server makers - wanted standardization to happen.
"We are not suggesting that IT organizations stay away from blades - blades do address many problems in the data center," explained Andrew Butler, a vice president and distinguished analyst (do you get extra pay for two titles?) at Gartner who put together the projections.
"What we are saying is that IT organizations adopting blades need to be prepared for further changes in this technology. Blade servers have been a rapidly changing technology, and we fully expect this to continue, particularly during the next five years."
Order of the Gartner
Gartner's report, entitled Blade Servers: The Five Year Outlook, offers a number of predictions for the near term and the longer term. Here they are:
- Blade server aggregation: This feature allows for two blades to be logically joined, creating a single logical server that can then be provisioned at the bare-metal level. Gartner predicts that logically joining blades to create single server blades from multiple physical blades will become a standard blade server capability by 2010.
- Faster input/output (I/O) connections: Fabric speeds are continuing to increase. 10 gigabit (10Gb) Ethernet is entering the market, equivalent InfiniBand speeds are coming and speeds for both fabrics will increase beyond 10Gb.
- Improved I/O controls: Blade vendors will deliver increased controls to aggregate, disaggregate and prioritize bandwidth to individual blades and virtual machines running on those blades. By 2011, increased virtualization adoption will make I/O quality of service controls a standard feature of blade servers.
- More flexible storage options: Storage technology associated with blades will advance to a point where storage can be added to a chassis and then assembled into storage area network pools and network-attached storage pools, or tied to blade servers in a direct-attached storage-like configuration.
- Deeper integration with virtualization: Gartner expects blade vendors to drive deeper integration between virtualization and blades, including support for embedded hypervisors and further integration of virtual machine management with physical machine management.
- Management software enhancements: Blade vendors are focusing on new functionality, integration and interface enhancements on their blade management tools, to help stimulate preference for blades over other form factors.
- Chassis interconnections: Today the chassis represents an infrastructure boundary. However, in three to five years' time, chassis interconnects will enable resources to be shared. Although Gartner expects this innovation to be introduced as a blade market capability, it will eventually become a valuable direction for other server form factors as well.
- Memory aggregation: Memory aggregation will enable one blade to use memory located on other blades in the server. The net effect will be to increase memory footprints for an operating system beyond the physical capacity of a single blade. This will further drive implementation of blade server aggregation to create larger-style, virtual symmetric multiprocessor designs. By 2012, memory and chassis aggregation will enable blade technology to address large vertically scaling workloads.
- Standards for switch modules: The current chassis do not currently support a common interface and as a result, third-party companies such as Cisco and Brocade must make unique products for each and every server vendor. This is inefficient use of their R&D resources. Gartner predicts an interface and form-factor standard will be introduced during this time frame to enable third-party companies to manufacture products common to multiple vendor chassis. However, it is unlikely that other blade- or chassis-related standards will be agreed on by major vendors during the next five years.