A big question facing data centre managers is how much the adoption of blade servers – servers contained on a card and installed in a space-saving multiple slot chassis - will depend on the development of industry standards for blade form and technology?
A first consideration is commonality of design. A standard chassis would allow customer who wished to swap vendors to replace one blade chassis with that of another vendor in the same space as the old. At present the lack of an agreed chassis design means that vendors have a better chance of ensuring customer loyalty.
CompactPCI is so far the only standard being used to define blade form factor and connectors. cPCI has been derived from PCI as used by PC add-on cards. In addition cPCi already defines the connectivity for Gigabit Ethernet and Fibre Channel fabrics.
But cPCI is not suited to high performance, high density, low cost environments but rather to telecommunications and industrial applications as opposed to traditional data center computing. So, it was perhaps not surprising that when HP called for cPCI (Compact Component Peripheral Interconnect) to become a standard in March last year it fell on deaf ears – despite being broadly endorsed by Dataquest, which said a common standard was essential to stimulate sales. Jeffery Hewitt, Gartner Dataquest’s primary analyst covering servers says: “A lack of standards will be the primary market inhibitor as many end users will be reluctant to install a blade server that appears to be proprietary. The acceptance of such a standard should help end user inhibition to install blade servers.”
Many detractors favour Infiniband, which is designed to replace PCI shared bus I/O architecture with a universal interconnect fabric that gives a wire speed of 2.5GBps. Most major Fibre Channel companies, storage companies, and server manufacturers are involved in the Infiniband communications standard but there are no standards for card size or conformation. The dilemma is that blade servers are getting established before Infiniband becomes available.
Perhaps a strong industry body is needed to push forward the standards debate. In October 2002 , the Blade Systems Alliance, BladeS (first called the Server Blade Trade Association) was formed to promote the adoption of blade systems by stimulating the dialogue among end users, consultants, analysts and vendors. Leading vendors are noticeable in their absence in the membership but Veritas and Unisys are on the executive board and the 30 plus membership includes Qlogic, Network Appliance and F5 Networks.
This lack of standards perhaps most concerns those seeking to use blades in storage environments. Geoff Barrall, CTO at storage vendor BlueArc, is typical of many who feel that users remain sceptical: "System administrators I speak to cite a number of reasons why blade servers do not make sense for their environment. Blade servers cannot be retired and replaced in the same way regular rack mount servers can, and there is a loss of flexibility in the way servers can be interconnected. In high performance computing environments, where the layout and design of server interconnection is paramount, this was seen as a serious issue. Potential lack of upgradability was also cited as an issue. Until blade servers overcome these limitations, it is exceedingly difficult to see how they will be able to expand their role from that of a niche sale."
But such concerns are not an issue for some end-users. David Hamilton, IT Director at law firm Freshfields said: “We use blade servers and expect 50 per cent of our servers to be blades within 18 months. Standards are not an issue for us. So long as they run Windows NT I don’t see a problem. Maybe standards are an issue long term but right now it doesn’t affect us.”
HP meanwhile is going ahead with a strategy that means delivering blades to meet any requirement. In early August it unveiled Proliant BL10e servers using low voltage Pentium M chips (see Techworld review) and thus allowing a chassis to hold hundreds of servers – something pioneered by startup RLX. At the other end of the spectrum HP unveiled the latest Xeon-powered blades to meet the need to run more demanding applications.
Customers are aware that there is vendor lock-in with blade products. What remains to be seen is if the benefits of space and centralised management will be enough to win them over.