FRAMINGHAM (10/02/2003) - As IBM Corp., Hewlett-Packard Co. and other system vendors push to market ever more powerful and lower-cost blade servers, evidence is mounting that these ultracompact servers may be ready to move beyond traditional applications such as Web server farms. But users and analysts say they're more likely to coexist with traditional rack servers than they are to replace them.
Blade servers reduce hardware components and save data center space by condensing the power and bulk of traditional servers onto a single high-density circuit board. These typically plug vertically into a chassis that's 3U or taller and slides neatly into a standard server rack. (A 1U device is 1.75 in. high.)
Blade servers can also be more flexible and easier to manage than traditional, rack-mounted servers. This flexibility comes from the ability to swap out different preconfigured blades into a single chassis as business requirements change.
But such advantages over compact 1U servers so far haven't -- and shouldn't -- make blade servers the automatic choice every time, analysts and users say.
A Different Architecture
"There's still a pretty considerable role in the universe not just for 1U servers, but for 2Us and 3Us," particularly where there's a need for local data storage, says Jonathan Eunice, an analyst at Illuminata Inc. in Nashua, N.H. "When you get to blades, which are sub-U density, you start to lose the space to put in disk drives."
Some blades, such as IBM's HS20, offer onboard support for a few disk drives. But most blades gain access to storage through a Fibre Channel link or across Ethernet. "That's a different architecture than many users are accustomed to, so blades mean a cultural shift to remote storage," Eunice says.
"There are times when a 1U (server) makes more sense," says Jeff Benck, director of blade server products at IBM. Specifically, if a user is looking to deploy fewer than five servers, blades aren't the right choice, he notes.
At the same time, developments in blades, such as the addition of more-powerful processors and new network and storage connectivity options, are enabling their deployment for a wider range of enterprise applications that must scale up instead of out, such as databases, vendors say.
HP's four-processor BL40p blade, for example, has dual onboard PCI-X slots that accommodate Fibre Channel host bus adapters for connecting to large storage-area network (SAN) clusters used in running corporate applications, such as messaging or ERP systems, says Sally Stevens, HP's director of blade server platforms. "This line of blade servers addresses enterprise-class applications. We can hit all of the applications a traditional server hits," she claims.
For Larry Scott, manager of server support at Dollar Rent A Car Inc. in Tulsa, Okla., cost was the primary driver behind the company's decision to move to HP ProLiant BL e-Class blade servers for a range of applications that includes front-end Web services to midlevel data center applications.
"Twelve months ago, when the whole industry was really constrained, (the ProLiant BL e-Class) was the lowest-end server you could get," Scott recalls. "Truthfully, we looked at (VMware Inc.'s virtualization software), but when HP came out with its Generation 1 blades, it was the same price as VMware, and we'd really prefer hardware over software. That was the tack we took."
Also, Scott pointed out that blade servers have "a fairly nominal learning curve." HP offers software tools to aid with blade server deployment, but these tools can also be used across rack and tower servers. "So it's not limited to blades," he notes.
Meeting Processing Needs
Another blade user, Keith Grimes, chief technology officer at Memphis-based Investigation Technologies LLC, which does business under the name of Rapsheets, says he chose IBM's eServer BladeCenter to more efficiently handle the ever-increasing processing demands of customers searching the 150 million criminal records in the company's database.
"We were using IBM cluster servers and clustering together four or five servers for redundancy and fault tolerance," Grimes recalls. Now, Rapsheets is running seven blades with dual Xeon processors that boot directly off a SAN. "There are no hard drives, and BladeCenter allows 14 blades to be on one Fibre (Channel) connection (to the SAN), thereby increasing the efficiency of the processing power vs. the storage," says Grimes.
BladeCenter also makes it easier to do distributed processing, he adds. "We may search a name up to 12 different ways, flip-flopping first and last names or using initials, and the way our application is written, we can spin off the searches to different blades and let them operate on their own to optimize the database and then return all of the results and aggregate them," he notes.
"I can search by first name, last name and date of birth and create an index. Then I can create another index on the last name and middle name. It's faster than having both indexes on one database," he says, adding that the turnaround time is less than a second.
Tne downside to blades is that they have problems with heat dissipation. "IBM has actually installed a blower on the back of the blade chassis that can get pretty loud. It sounds like a small jet engine or several hair dryers taking off at once," Grimes says. Rapsheets houses the server rack in a separate, air-conditioned room. Users considering migrating to blades should plan for their cooling equirements accordingly, Grimes notes.
A sampling of options from major server vendors
- Offerings: HP's BL series includes one- to four-processor blades with optional support for two onboard 2Gbit/sec. Fibre Channel host bus adapters in its BL40p blades. HP also offers a high-density, single-processor BL e-Class server line.
- Differentiation: HP is the only vendor currently offering four-processor blades.
- Offerings: Dual-processor HS20 server blades for its BladeCenter line; IBM plans to introduce a four-processor blade with SAN connectivity later this year. IBM's blades include integrated Gigabit Ethernet.
- Differentiation: IBM claims it was the first to offer an integrated Layer 2-7 Ethernet switch that plugs into its blade chassis. Functions include routing, application health checking, network and application load balancing, and embedded security.
Sun Microsystems Inc.
- Offerings: The Sun Fire B1600 Blade Platform supports up to 16 blade servers based on Sun UltraSparc processors or Intel Corp. x86 processors in a 3U chassis. The x86 blades will run Solaris or Linux; Sparc blades run only Solaris.
- Differentiation: Sun is the only vendor to offer mix-and-match operating system capabilities on its blades.
- Offerings: Dell's dual-processor PowerEdge 1655MC accommodates up to six server blades in a 3U chassis.
- Differentiation: Dell touts its free Open Manage Remote Install tool that lets users set up and capture an image of the server operating system and transmit it across a network to configure new blades.
RLX Technologies Inc.
- Offerings: Offers blade servers that use both Transmeta Corp. and Intel processors. RLX ServerBlades plug into a chassis and include dual onboard Ethernet connections and up to two hard drives. Its performance blades include support for dual 4x InfiniBand or 2Gbit/sec. Fibre Channel adapters.
- Differentiation: RLX says its blade-server management tools are its biggest advantage.