How data centers implement high-density server configurations

From a theoretical point of view, the server is a http://www.aliyun.com/zixun/aggregation/16327.html "> network environment of High-performance computers, it listens to other computers on the network (client) submitted by the service request, and provide the corresponding service. To this end, the server must have the ability to assume service and ensure quality of service.

But this explanation is still more esoteric, in fact, the server and the function of the PC is similar to help people to deal with information tools, but the location of the two different, personal computers (referred to as personal computer,pc) is designed to meet the needs of individual versatility, The server is designed to meet the needs of many users at the same time processing data. How do many people use the same server at the same time? This can only be done through the Internet, to help achieve this common use purposes.

Let's look at the functionality of the server, server can be used to build Web services (we usually see the Web page of the page data is stored on the server for people to access), mail services (we send all emails need to be processed by the server, send and receive), File sharing & Print sharing services, Database services. All of these applications have a common feature, they are not oriented to a person, but a large number of people, while dealing with a large number of data. So the server and network are inseparable. Can be said to leave the network, there is no server, the server is to provide services, only in the network environment it has the value of existence. The personal computer can complete the host's data Processing task in a single machine.

In the high tide of data center popularization, server consolidation and virtualization are two main trends. With the development of integration technology, the data center has focused more on SAN and NAS technology and the propulsion of the blade server architecture.

Virtualization is another way of consolidating. With virtualization technology, you don't have to do a lot of servers with limited resources. You can virtualize them to fewer but more powerful machines, saving hardware costs and power consumption.

If you follow this line of thought, the next step is almost there-if you combine Blade server, SAN, and virtualization technology, you can achieve high-density server configuration, and the effect will grow exponentially compared to any of these options.

What is a high-density server configuration?

The goal of a high-density configuration is to place as many servers as possible in a small space. In this way, blade servers are ideal because you can place some blade servers in 10U racks, while ordinary servers of the same size need to occupy 16U of racks.

In many cases, the blade has the same strong performance as a normal server for a 1U or 2U rack, so you can increase the configuration density without sacrificing power. Of course, the blade has a typical feature, that is, its disk expansion options are relatively small, but we can consolidate its storage performance through the SAN, so this lack of it becomes irrelevant.

Next comes the combination of virtual machines and servers. Server virtualization allows you to place 3 to 33 (or more) virtual hosts in a single physical machine. The extra server density you get from virtualization will of course vary greatly, depending on the power of the blades you deploy and the hardware requirements of your virtual hosts. The key is that if each server can hold four virtual hosts, you can increase the server density to four times times.

High-density server configuration benefits from virtualization software

If you use advanced virtualization features, such as VMware VMotion with Distributed resource Allocation (DRS), high-density servers can play a larger role. Vmotion allows you to migrate a virtual machine from one physical host to another without downtime. DRS is a step closer to helping you load virtual machines evenly across multiple hosts, ensuring that all of your physical hosts can share equally.