The following considerations can help you decide if/where/when blades fit best into your consolidation project...
Blades offer significant space savings compared to rack-mounted servers. Because of the high density of blades, however, you must include power and cooling considerations in the planning. Maxed-out chassis and racks may overburden both your ability to provide power and to cool your data center space.
In some cases, consolidating servers back into the data center using traditional rack servers can push the edges of available space, which means new data centers must be built. In these cases, blades offer tremendous savings in cost avoidance. When a new data center must be built, regardless, designing the new facilities with blades in mind (for both power and cooling) can create a new facilities' model for a true next-generation data center.
Remote location versus central location
If you plan to consolidate but will continue to have servers residing in remote locations, blades can significantly ease your management problems. Blades have strong remote management capabilities, meaning central IT technical staff can fully manage the blade systems at the remote location for every task except physically swapping hardware. The blade chassis management modules provide remote capability down to bare metal, allowing hardware diagnostics, reboot and even power-off functions to be performed remotely. Blades also simplify the necessary onsite physical tasks with easy-to-read indicators that show which blade has failed and the ability for even non-technical staff to swap out a failing blade and replace it with a new one (which can then be re-provisioned remotely).
Blade management functions can be integrated with other management tools such as IBM Director, HP Insight Manager, Dell OpenManage and Microsoft management tools. An increasing number of software tools are becoming available to assist in the deployment and provisioning process from the big vendors as well as from smaller companies like Altiris, Cyclades (acquired by Avocent Corp.) and Ardence Inc.
Follow the sun provisioning
If you are consolidating servers to a central location and have servers sitting idle during off-hours at that location, re-provisioning those idle servers to other applications and regions based on time zone changes can offer additional consolidation and savings. With their modular approach, blades can facilitate this process when combined with deployment and provisioning software that is available today. The process is even easier if the blades are anonymous (diskless blades) and get their storage (and even boot) from the storage area network (SAN). Virtualization software adds another layer of manageability here by allowing provisioning of virtualized servers from anywhere and at anytime within a pool of available blades.
Number of servers
Because blades share common components within the chassis, expect an upfront investment cost for the chassis and for the first blade. Typically, the break-even point to cover those costs comes at five to six blades per chassis. So, if you have less than five servers at a given location and are not expecting significant growth, blades are probably not the right choice. As more blades are added within the chassis, the cost per blade decreases because they are sharing common facilities (power, cooling, switch modules, etc.). Depending on your cooling ability within your data center, however, you may be able to operate fully configured chassis and racks of chassis. Involve your facilities management technical staff in this part of the evaluation, planning and implementation process.
Type of applications
Although CPU power continues to increase on blades, blades may not keep pace with the upper end of high-performance computing clusters. Applications requiring heavy CPU power and many processors within a single system image (scale-up applications) may be better suited for rack servers (although some blade vendors in this space would argue that point). Conversely, scale-out applications requiring lots of servers running the same application (e.g., Web servers, some application servers, some database servers) are an excellent fit for consolidating and managing blades.
Another area that is gaining traction with blades is the "data center in a box" approach, in which a blade server system is configured with all the components needed for a remote site. For example, you might configure a chassis with Web server(s), application server(s), database server(s) and switch modules, along with firewalls and load balancers and whatever storage or storage connectivity is appropriate (NAS or SAN).
Blade vendor choices
Although it would be reasonable to assume that blades are standardized and that blades from one vendor can be mixed with blades from another vendor in a blade chassis, sadly this is not the case. The only standard for blades is the ATCA standard in the telco space, and not everyone follows that either. In standard blade servers, the chassis and blade design is proprietary, so if you buy the IBM BladeCenter Chassis, you install IBM blades. Likewise for the HP BladeSystem, the Dell PowerEdge, etc.
This has led many users to select their blade vendor based on their historical dominant systems vendor. But it is worth evaluating all the options in the blade space, because each blade system has unique aspects. In addition, you'll find a number of strong niche players in the blade space that are not traditional systems players (e.g., Egenera and Verari) but who bring their own advantages.
The modularization, use of space and manageability of blades make them an excellent option for consolidating servers while also laying a strong foundation for the future. This column, along with the previous column on blades and consolidation, offers a starting point for evaluating where blades might fit in your environment. Adding virtualization software into this mix offers additional benefits in manageability and ease of provisioning. In future columns, watch for tips on how to use virtualization with blade systems to create the next level of manageability in your data center.
What other areas of blades and virtualization are hot for you? Networking your blades? Blade storage considerations? Power and cooling issues? CPU chips and memory advances? Let me know your hot topics.
Barb Goldworm has spent over 25 years in the computer industry in various technical, marketing, sales, senior management and industry analyst positions, with IBM, Novell, StorageTek, Enterprise Management Associates, and multiple successful startups. She is the founder and President of Focus Consulting, a research, analyst and consulting firm focused on storage and systems. She is currently working on a book on Blades for Wiley and Sons. Barb can be reached at email@example.com.