With the high cost of data center floor space and current advances in technology, new installations with denser cabinets that require more powerand cooling continues to be the trend. Besides the challenges that new installations present, equipment cabinet upgrades can also be a problem asthe existing power and cooling currently provided may not support the new cabinet configuration. Surveys show that Information Technology equipment is typically replaced every 2 to 5 years depending on theindividual organization and its needs. Surveys also show (See Chart 1) that when asked about their top 3 concerns; Heat/Power Density is the number one concern of Data Center Management.
High density applications like cluster server configurations have in some cases pushed the kW power demands as high as 40 kW per cabinet. The required power depends on the equipment, how dense the cabinet is and whether redundancy is required. This has led to new and innovative solutions for providing cabinet level power utilizing CDU’s (Cabinet distribution Units).Distributed server architectures based upon "blades" are rapidly emerging in the data centers of corporations and Internet service providers. Historically, servers only assumed the form factor of a re-purposed desktop computer or rack-mountable appliance. These servers utilized high-quality components and leverage additional memory and hard disk capacity. Now server form factors are evolving into single PC cards that can be plugged into a chassis as a single module. Bladed servers stack numerous independent lower-end servers within a single chassis. Chassis can accept anywhere from eight to 24 blades. Each blade is an independent system with its own memory, processor and network connection. Due to their compact size, multiple blade servers can be placed in a single server rack or enclosure, allowing numerous systems to share electricity and HVAC resources. Gartner Dataquest predicts that worldwide server blade shipments will increase from 84,410 units in 2002 to more than one million in 2006. The IT research firm anticipates that revenue from server blades will reach at least $1.2 billion during this time period. Blades are thus becoming the one major segment of the server market that is experiencing escalating growth. The popularity and fast growth of the blade server can be attributed to cost-savings that the device accrues to its users, especially hosting firms and service providers. Because more than 250 blade servers can be effectively placed into a single rack, it is possible for hosting firms with data center operations to quadruple their hosting capacity with the devices. By comparison, most of today's low-end servers have only a single computer in one enclosure, allowing only one 42 systems to fit in an industry-standard rack. Because blade servers are small, consume less power and generate less heat than an average server, they are emerging as an ever-popular option for niche Web hosting services. With the cost of data center space at approximately $300 per square foot and with energy costs increasing throughout continental North America due to deregulation, blade servers have become the de facto standard for increasing data center profitability. The systems are typically used as Web servers and caching servers that deliver Web pages to Internet browsers, SSL servers for encrypted communication, and streaming servers for audio and video transmissions. Most hosting companies and service providers appreciate the devices because they are easy to install and employ dedicated software that improves their administration, performance and reliability. The devices are also increasingly being utilized as firewall devices and to increase capacity in corporate data centers. Blade severs are excellent devices for hosting companies with large existing data center deployments who want to capitalize upon existing PCI expansion space. The inclusion of a single blade allows a hosting company to double its computing power or hosting offering, utilizing the same amount of physical space. The main disadvantage concerning PCI-based blade servers is that the processors are usually not as robust as traditional high-end servers. This factor limits the use of the server to functions such as low-end Web hosting. While blade severs have the capacity to serve streaming video and other demanding applications, often the emerging technology is used for back up or storage purposes. Lower-end models usually depend on server or operating system virtualization, causing the server to run much slower than traditional equipment. It is thus incumbent upon a reseller to determine whether a hosting company is utilizing blade servers for mission-critical deployments and whether those servers can accommodate demanding applications. Resellers who operate their own equipment might want to consider utilizing blade servers as an effective technology to add firewall or other security specific capacities to their collocated equipment.
Since blade enclosures provide a standard method for delivering basic services to computer devices, other types of devices can also utilize blade enclosures. Blades providing switching, routing, storage, SAN and fiber-channel access can slot into the enclosure to provide these services to all members of the enclosure.
Blade vs. Rack mount
Blade servers are outgrowing at a faster rate than traditional rack mount servers. A recent Gartner study found that blade servers are the fastest growing segment of the server market. One reason is simply because blades are easy to configure and manage. Using a blade can be as easy as using an expansion card — only this "expansion card" comes with one to four processors, memory and disk storage. Blades are considered to be hot-swappable, which means you can add new blades or remove existing ones while the system is powered on. Traditionally, blade servers have been deployed in data centers and large enterprise environments, but the small business is looking at blades for the same reason enterprise has previously: They take up less floor space than traditional rack mount servers, they require less power and fewer IT management resources are required than with a rack mount. Blade servers are scalable to any physical infrastructure.
It is important to remember that blades are not suited to all applications and cannot replace a large-scale server in all instances. There is an also proprietary interest at stake. An HP blade, for example, cannot be plugged into an IBM blade chassis. As a result, third-party vendor blades have to be designed for specific branded chassis.
Blade vs. Rack mount — A Quick Comparison
Blade Servers Rack mount Servers
Shared infrastructure for fans, power supplies, Ethernet switching, storage. Networking and storage is built into the chassis, which eliminates cables.
Each has its own power supply, fan and cables.
Small form factor can use up to half the space of a rack mount server.
Large physical floor space required to house rack mount.
Installation requires no special tools or expertise, semi-technical or non-technical staff can deploy the blades. Able to hot-swap.
More difficult deployment. SMB may require on-site technicians to make additions to the rack mount.
Proprietary nature limits the ability to mix and match components from multiple suppliers in one chassis.
More choice in system suppliers for acquisitions. Multiple components from different suppliers can be used in one chassis.
Many blades still have cooling issues due to shared cooling on the chassis
A variety of rack mount coolers are available. Separate fans help cooling issues.
Virtualization & Common Blade Server Computing Environments
Virtualization is another area of computing that has been a driving force behind blades. Virtualization involves emulating multiple servers on one hardware platform. Running multiple operating systems on a single computer or storage virtualization where you have the the amalgamation of multiple network storage devices into what appears to be a single storage unit are examples of virtualization. With a blade server you have the option to combine blades with virtualization software to consolidate workloads, each running on its own instance of the OS (using the same or a different OS). With blades, separate operating systems and applications can co-exist on one server and users of the system are able to access more memory and processing power as their workload demands it.
Blades are frequently deployed in data centers and high-performance computing environments (a branch of computer science that concentrates on developing supercomputers and software to run on supercomputers.), and can serve as application servers, databases, e-mail or Web servers, and more. Large data centers and telecommunications service providers benefit from the use of blades as they provide the means for a large business to respond quickly to changes in business conditions. High-traffic Web sites are another example of where blades can help — if you plan to host an online event, broadcast events live or something of that nature blades are a perfect solution as they allow you to quickly add memory and processing power to compensate for unusually high traffic to the Web site.
Overall, where a business or group would use several different servers for different applications, it makes sense to combine the multiple servers into one blade server to make for better manageability. Blades are often viewed as a solution for large enterprise, but really the IT cost and manageability of a blade solution makes it well-suited for smaller businesses and organizations. To this end, many of the main blade vendors market specific blade solutions and packages to the SMB.