Plenty of users are surprised by the cost of a blade server project, according to Anne Skamarock, research director at Boulder, Colo.-based Focus Consulting and co-author of Blade Servers and Virtualization: Transforming Enterprise Computing While Cutting Costs. "A fully populated blade system may require more cooling and power than a fully loaded rack system," she cautions. And if you don't have a storage-area network (SAN) in your data center, you should establish one as the foundation for a blade project, she added.
"That's an upfront investment you should make as you prepare for a growth strategy with blades," Skamarock said. Many analysts will tell you that real returns on blades can only be seen when you buy enough blades--more than eight--to cancel the price of the chassis.
In addition, the popularity of virtualization -- a natural technology companion to blade infrastructures -- is helping to drive the adoption of blades.
Martin MacLeod, a London-based consultant who authors a blog on blades in his spare time, said users are being inundated with an impressive range of options from vendors trying to take advantage of the consolidation and virtualization craze. He has dedicated a spot in his blog for "peripheral blade vendors" as technologies converge. In his practice, he often fields questions about purchasing and chargeback, he said. "The first blade encounters all of the cost: the new enclosure, the power supplies and the switches," he noted. "So if HR requires another blade, do we need to buy another enclosure? Is that an HR cost or an IT cost?"
Before you commit to a particular blade vendor, here are some points to consider to make sure the technology fits with your data center requirements.
- Are there any prerequisites for a diskless server or server boot over SAN options?
- Is there a set storage requirement per blade? Will it ever change?
- Which level of tech support will be provided? Is there a different level for Fibre Channel (FC) users?
- Request a vendor compatibility/interoperability matrix. Blades are a proprietary technology.
- Will you need disk drives on your server blades? Are they hot swappable?
- Don't assume that a fully loaded blade system won't cost as much to power and cool as a fully populated rack. Ask vendors to help with projected power needs and possible savings.
- What remote management features are included in the price? Some may be priced on a per-server basis.
- How many blades are supported in each chassis? Will you need a second blade center to support your growth strategy?
- Will special power connectors or cabinets be required?