From GHz to memory, understanding the nuts and bolts of your next server purchase can make you an informed buyer and help determine the features most important to your organization, as discussed in "Understanding server options: How to assess your business requirements." But knowing how to distinguish what you want vs. what you need can help you zero in on server requirements, and even make room for some extra features, as you make your purchase.
Do you have free space in cabinets or racks for an additional server? If you have a blade system, do you have room for an additional blade? Free space in cabinets and racks and even any available floor space can -- as far as physical packaging goes -- influence the type of server you should consider.
For example, if you are out of available floor space but have room in cabinets or racks, you may be forced to find a server to fit those confines. On the other hand, if part of the role of the new servers is to consolidate older systems, which would free up more room in the future, you will still need temporary space during the transition and upgrades.
Physical-, facility- and environmental-based considerations (think: habitats for technology) include power, cooling and heating, ventilation and air conditioning systems, and will also affect your server requirements. Keep in mind where your available primary power source is and where your uninterruptable backup power supplies and generators live. While there may be enough floor, rack or cabinet space, there may be a constraint on the accessibility of power or cooling capacities.
And when it comes to power, efficiency is king. Many energy utility companies provide incentives, rebates and other programs to reward efforts in power conservation and efficiency. While some rewards are based on the overall reduction of energy consumption via consolidation or upgrades, others reward reducing or maintaining the power footprint during business growth (i.e., doing more with what you have).
Similar to shopping for home appliances, when searching for energy-efficient servers, look for those that are Energy Star server-certified or qualified. These often have advanced intelligent power management features and 80 Plus efficient power supplies. Check with your local energy and solution providers for a list of available programs. But start early -- some programs must be initiated before beginning any upgrades.
Do you need a SAN or NAS?
While there is a trend toward networked and shared storage using storage area networks and network-attached storage, many servers still have built-in disk drives. For those applications or environments where dedicated internal storage is still needed, there are many options in terms of performance and capacity -- with most shifting toward the physically smaller and energy-efficient 2.5-inch SAS devices. Many servers are also either shipping with or provide as an option PCIe SAS RAID adapters for boosting the performance of internal and external storage.
Understanding server performance: Measure and compare
Server performance comparisons can be disparate, like comparing apples to oranges in even the best-case scenarios. With this in mind, when evaluating servers, consider performance at low power-setting modes as well as the energy and cooling server requirements during normal and heavy processing times.
Also factor in all of the metrics that can be used to determine server performance: percent of CPU processor utilization, response time, number of transactions, messages, compute operations, I/O operations, files or videos served per second and the number of MHz or GHz. However, effective performance should be measured by how well all of the components work together under different load or work conditions.
There are many different workload similarity and benchmarking tools (including Iometer and Microsoft ESR, as well as those from Standard Performance and Evaluation Corp. and the Transaction Processing Performance Council), but the best test and comparison tool is whatever most closely resembles the application or workload the server will be supporting.
Understand your server needs and categorize these requirements into three groups: What you need, what you want and what you would like to have. It may sound simple, but it will ensure that your basic server requirements are met and are not changed by others in an attempt to sell you on more advanced or optional features during the acquisition process.
Bottom line: Be an informed buyer and do your research. Understanding server requirements and all the server options and functionality available will ensure that you are meeting the needs of both the business and IT.
Greg Schulz is founder of The Server and StorageIO Group, an independent IT industry advisory and consultancy firm based in Stillwater, Minn. He is also author of the books The Green and Virtual Data Center (CRC) and Resilient Storage Networks (Elsevier). Follow him on Twitter at @storageio.