Product Reviews

Dell's entry into the lucrative world of blade servers was a comparatively low-key affair. Its first product was the distinctly lacklustre PowerEdge 1655MC, which offered a modest specification from its 3U chassis and has since disappeared into obscurity. The PowerEdge 1855 now represents Dell's sole blade server offering and looks a far better bet for a number of reasons.

The most obvious is the fact that Dell has sourced this product from the same company that Fujitsu Siemens uses. At its foundation is a chassis identical to the Primergy BX600, which impressed us when we first saw it. The server is aimed at enterprise data centre and ISP/ASP applications and delivers an excellent specification that competes strongly with IBM's eServer BladeCenter. At 7U, the 1855 chassis is the same height as the BladeCenter, although its complement of ten blade slots delivers a lower processing density for a 42U rack cabinet of 120 Xeon processors. The chassis itself is well built, and fault tolerance is easily a match for the BladeCenter, as it was supplied with the full complement of four 1,200W hot-swap power supplies.

Network connections extend to a hot-swap PowerConnect 5316M switch blade, which provides 16 Gigabit ports. Of these, ten internal ports are linked to the chassis backplane and six presented to the outside world. Two modules allow the blade's Gigabit ports to be routed through to different switch modules for redundancy. Two more bays are provided for another pair of 5316M switch blades, but to use these you'll need to install an extra dual-port Gigabit Ethernet daughtercard on each server blade. A feature that's been absent from a number of blade-server offerings is support for Fibre Channel (FC), but Dell remedies this with a complete new range of modules and blade add-ons. The blade supplied came with Dell's 2342M daughtercard, which utilises a QLogic 2342 HBA chipset and extends FC connectivity to the blade. Other options are a second dual-port Gigabit Ethernet card or a Topspin InfiniBand card, making the Dell proposition highly versatile. For the chassis, you have a wide range of choices. Dell offers four-port Brocade Silkworm 3014 or McDATA 4314 FC switches, or a simple FC passthrough module.

Server

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blade build quality is easily up there with IBM and HP. The dual-processor review machine was equipped with one 3.2GHz Xeon along with 1GB of PC3200 DDR2 memory. A valuable feature in the storage department is that each blade supports two hot-swap Ultra320 SCSI hard disks, and combining these with the integral Dell PERC 4/im RAID controller allows fault-tolerant mirrors to be created. This was a failing on the BladeCenter, but IBM has since remedied this on the new HS20 server blades, which support up to four small-form-factor Ultra320 SCSI hard disks. The Dell blades have the processors fitted just behind the drive bays and are topped off with large passive heatsinks, while at the rear is a bank of six DIMM sockets that supports up to 16GB of DDR2 memory. Dell also recently announced that it would be fully supporting the next generation of dual-core Xeons.

The front of each blade provides plenty of status information along with power and KVM selector buttons. A proprietary port allows two USB devices and a monitor to be connected with the supplied Y-cable.

Chassis configuration starts at the DRAC/MC management module. With a serial port connection, we were able to access the Ethernet switch and assign the default VLAN with an IP address. Moving over to the switch's web interface provided full access to areas such as port configuration, QoS, link aggregation and a wide range of security features, including 802.1x port authentication using a RADIUS server. A graphic on the homepage also shows the link status of all internal and external ports. Access to each server blade can be achieved via the integral Avocent-based KVM switch, which is supplied as standard and supports both local access to each blade and remote access via KVM over IP.

Server deployment, management and monitoring are handled by Dell's OpenManage software bundle. OS image deployment isn't covered in any depth in the documentation, and we found it easier to connect the supplied USB CD-ROM drive to a server blade front panel and use the bundled Server Assistant to install an OS. The Server Administrator provides web-based access to individual servers, allowing you to gather data from the motherboard sensors and view status graphs of power, temperatures and voltages. Comprehensive alerting facilities use thresholds assigned to each value and allow warnings to be linked to network broadcasts, sending emails and running an application.

Dell's server blade management features are on a par with Fujitsu Siemens' ServerView and HP's Insight Manager, although the latter's Rapid Deployment Pack is one of the best on the market for server provisioning and OS deployment. Where the PowerEdge 1855 wins is for a good range of features at a low price, including excellent FC support and the promise of dual-core Xeon server blades.