The journeyman serverNot all pizza-box servers are the same. The journeyman category we're examining is the middle segment of a continuum bordered on the low end by value-oriented servers used by SMBs, and on the top end by heftier models, such as the virtualization-oriented systems I examined in a previous review (see "InfoWorld review: Dell's virtualization servers surge ahead").
Virtualization servers are designed to host many virtual machines. As a result, they typically have higher RAM and processor requirements. In addition, they tend to devote less space to on-board I/O, as the data for the VMs is almost always located in a spindle farm and piped to the virtual machines. This design enables virtual machines to migrate easily among hardware platforms -- a principal value of virtualization.
While the virtualization servers generally sport four processor sockets to provide the computing heft, the journeyman servers are mostly two-processor affairs. This is because a dual-processor system is significantly less expensive, and it is more easily replaced in the event of failure. In other words, the two-CPU boxes are cheaper, and by running fewer tasks they represent a less disruptive point of failure. The preference for dual-processor systems also has drawbacks of course, not least of which is the additional complexity and cost that each incremental system imposes. These costs include software licenses, ports on the net, and the like.
In terms of I/O, journeyman servers tend to have a large complement of disk drive bays on board. They do not adopt the virtualization server's approach of diminishing local I/O devices. For example, the Dell and HP models have bays for 8 hard disks, while the Lenovo has room for 12 drives, 4 of which can be swapped out for a tape system. These systems use high-speed 2.5-inch drives spinning either at 10,000 or 15,000 rpm. On the Lenovo, these drives had a capacity of 300GB, so configuring these servers with multiterabyte high-speed storage is entirely possible. This means that sites can add server capacity without necessarily increasing the network traffic or the number of network storage devices.