Blade servers are increasingly finding their way into small and medium-sized businesses (SMBs) as cost and space-saving
benefits are realized. Whether you need to consolidate servers for more physical space, save energy or both, blades have a lot to offer -- if you know what to look for.
SMBs most commonly use blades for packaging multiple servers into smaller, denser enclosures while sharing some common infrastructure items such as power, cooling and a keyboard, video and mouse (KVM) switch to take up less space.
Blade servers are beneficial to SMBs because of their modularity, which allows growth and flexibility without compromising processing capabilities. With the growing focus and awareness around power and cooling, blade servers can also provide advantages for physical server consolidation to reduce your energy footprint.
Here are some factors to consider before you decide to implement blade servers:
- Determine power requirements. Check with your vendors as well as your facilities staff or electrician on what you need for electrical power and type of power connectors to support various blade server centers. Many blade server vendor Web sites have power calculators and other tools to help determine potential electrical power savings.
- Project growth plans and capacity requirements. Look at your growth plans and requirements for server performance, memory, storage and I/O performance capacity, network bandwidth and connectivity. How will a blade center accommodate these plans? What options exist for enhancing individual blades with more processing power, I/O capabilities or memory? Remember, the number and size of server blades in a blade center chassis will vary from vendor to vendor as well as across their different blade families.
- Determine interoperability and networking connectivity options. If you need to interoperate with existing storage and networking technologies, what are the compatibilities and what type of I/O and networking connectivity options will you need? Investigate if a specific blade center enables enough network and storage connectivity to meet the demands of all server blades for active, high-performance environments. If you are combining blade servers with server virtualization, keep in mind the aggregated storage and network I/O requirements.
- Inquire about server and storage area network (SAN) interoperability. Check with your vendors about interoperability and prerequisites for a diskless server, or server boot over SAN options. Server blades are available with various options similar to traditional rack and stackable servers, including amount and type of processor cores (Intel Corp., Advanced Micro Devices); amount of memory; different types, capacities and quantities of disk drives; and I/O connectivity options. For example, some blade servers support mezzanine cards that can be used to add an additional PCI, PCI-X or PCIe adapter such as Ethernet, Fibre Channel or InfiniBand.
Questions to ask vendors
Ask each vendor the following questions:
- Does the server include a KVM switch for managing the blades, as well as CD/DVD and USB port capabilities?
- What are the networking and storage I/O connectivity options? Will the server work with your existing environment?
- How many blades are supported in each blade chassis?
- What types of processors, number of cores and I/O capabilities exist per blade?
- Which operating systems are supported on the different server blades?
- Will you need disk drives on your server blades and are they hot swappable?
- What are the power and cooling requirements?
- Are special power connectors or racks and cabinets required?
Blade centers provide flexible resource allocation with varying grades of granularity. For example, by portioning a physical server blade using server virtualization software, you could have fine-grained allocation of server resources to run multiple operating systems on one blade. For more coarse allocation, you could assign an entire blade without using virtualization software to run a dedicated operating system and applications. In a blade center, some blades could be configured to run Windows-based applications, while others could run Linux, Novell or Unix operating systems and applications.
Server blade centers are modular, which means companies can mix and match various types of server blades (from the same vendor and in the same blade family) as well as networking and I/O connectivity options to meet specific needs.
In some configurations, it's possible to have a server blade center in the same rack as a network blade switch, along with a storage subsystem as a data center in a rack approach. Larger environments may have entire racks or cabinets with multiple blade centers, which are the chassis that hold the individual server, I/O, networking and storage blades.
Many vendors offer blades and high-density racks, including Dell Inc., Egenera Inc., Fujitsu-Siemens, Hewlett-Packard Co., IBM, Opensource Systems Corp., Rackable Systems Inc., Silicon Graphics Inc., Sun Microsystems Inc. and Verari Systems Inc.
You can learn more about blade servers, blade centers, blade switches and associated software at the various vendor sites mentioned at www.blade.org.
Greg Schulz is founder and senior analyst of (The StorageIO Group in Stillwater, Minn., and author of the book Resilient Storage Networks (Elsevier B.V.). Let us know what you think about this tip; email email@example.com.
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