The Win7 system's attention when it comes to virtualization

There are a lot of things you need to be aware of to achieve virtualization on Windows 7. Specifically, you need to pay attention to the following aspects of the content.


One, you need to pay attention to the maximum CPU utilization.


now most enterprise's server, its CPU processor utilization rate is only about 5%, very few server's CPU utilization rate will be over 10%. For this reason, this means that there is too much processing power on the server to be exploited. Through the virtual server, the integration of multiple application services on a server can help enterprises to reduce the cost of information projects and improve the utilization of resources. However, it should be noted that after implementing virtualized servers on the server, how much is the utilization rate of this CPU appropriate? Some system administrators may have misunderstandings in this area, and they will think that reaching 80% or 90% is reasonable. Fact According to the author's experience, regardless of whether the use of virtual servers, the server's maximum CPU load is only about 60%. If this load is exceeded, the application services deployed on the server will be adversely affected. The user's access to the server's resources is significantly reduced. So be sure to be aware of this when implementing virtualization applications on Windows 7. Do not set the CPU load too high. Typically, if virtualized applications are implemented on the WINDOWS7 operating system, the average CPU load is best controlled around 60% after integrating multiple application services. Maximum (such as backing up data on an application server, and so on) cannot exceed 80%. Otherwise, the performance of the application server will drop dramatically.


II, pay attention to the impact of I/O on virtual server performance.


Theoretically, the Windows 7 operating system supports up to more than 10 CPU processors and also supports a large amount of memory. However, it should be noted that sometimes the more the CPU or the larger the memory, the better the performance of the server can not be represented. Sometimes, even if a lot of CPU or memory is configured, the actual load rate is very low. However, the performance of the application server is still not ideal. What's going on here? Because the size of the CPU and memory determines the performance of the server to a large extent, it is not the only determining factor. When CPU and memory are no longer a factor in the performance of the server, I/O capabilities can have a significant impact on server performance. Especially in the context of virtual servers.


Use Hyper-V technology to centralize application services that are distributed on five servers to be implemented on a single server. What will happen at this point? First, the network traffic that would have been dispersed over five servers should be concentrated on a single server. In other words, now the virtual server to deal with the burden of CPU and memory, more importantly, the same network card, the same network cable needs to transmit more data. Second, after using the Hyper-V virtual server, the data read is also done on the original hard drive. This means that the hard disk I/O burden will increase exponentially. To do this, if the CPU and memory configuration of the virtual server is really good, the load rate is only 3% before the virtual server is deployed. Even if the virtual server integrates multiple application servers, the load rate is only about 40%, which is acceptable. But at this point it is possible that performance is not as good as the system administrator might think. This is mainly because the bottleneck affecting the performance of service applications on virtual servers is the I/O capability (throughput of network networks and the throughput of the hard disk), not CPU or memory.


This is like the relationship between the room and the elevator in the development of commercial housing. Developers have this strength, although can build high-rise buildings, the higher the building, the more rooms. This is like the higher the virtual server configuration, the more application servers can be merged. But when there are more people in and out of the building, the building can accommodate millions of people, but due to the limited number of elevators, their access will be greatly restricted. They had to spend a long time waiting for the elevator. This makes the performance of the I/O capability inadequate. To this end some of the high volume of buildings, such as shopping malls and so on, even if the area is not large, it must be equipped with a number of elevators to disperse passenger flow. This is the same reason as the virtual server.


for this reason, the system administrator may need to adjust the hardware configuration as appropriate if multiple application services are merged with virtualization technology on the server. such as a hard drive with better I/O performance. Or use disk array technology to improve the I/O capability of the hard disk. Either configure multiple network adapters on the virtual server or deploy the virtual server to the backbone routers to improve the performance of the network transmission. In short, the performance optimization of its servers becomes more complex, regardless of which virtualization software is used. To this end in the use of Hyper-V, the author of the system administrator's advice is prudent. In particular, enterprises already have more than one entity server, not to fashion, and the use of Hyper-V virtualization technology to integrate them on the same server.


third, good at using snapshot technology. (material)


Snapshot technology is a very powerful feature of Hyper-V virtualization software. Customer session snapshots in Hyper-V use Microsoft's VSS technology to capture the image of a file on a server. This snapshot technology is not only available on a single server, but can also work well in virtualized server environments. In a real-world production environment, it is used as usual for fault tolerance and disaster recovery.


an image can be rolled back to the previous state through a client image snapshot. This client image snapshot is useful sometimes when a system administrator is testing a deployment scenario. When the application environment is set up, the system administrator needs to conduct a detailed test to determine the availability of this scenario. But unfortunately, in the process of testing will produce a lot of garbage data. To do this, it takes a lot of time for the system administrator to delete this junk data after the test is done. To this end, some system administrators would rather risk the application environment is not perfect, also do not want to set up a good application environment for detailed testing. For this purpose, system administrators need to be adept at using customer image snapshots in the process of implementing virtualization. When the snapshot technology is available, the garbage data generated during the user's test or some destructive tests performed do not require manual clarity. A snapshot technique can be used to roll back an impression to the previous state.


Another snapshot technique is also useful in software demonstrations. As the author because of the relationship between the work, often need to give customers training and demonstration. If you have the support of snapshot technology, then the author can add delete information, adjust the software settings, modify the customer impression of the software information and so on. After completing the training or demonstration, I do not need to do the reverse operation again. That is, you do not need to go back to delete the changes. Or, for the next demo, you don't need to recreate the image from scratch to demonstrate again. At this point, I just need to roll back the image to the snapshot before making changes to the impression. With such repetitive rollback impressions, the author can perform the same process repeatedly without doing the reverse operation. As far as I know, many of the Microsoft System trainer or sales staff in the training and demonstration of the time, the use of this snapshot technology to facilitate the re-use of resources. So whether or not the enterprise needs to implement virtualization policies, the snapshot technology system administrator for this hyper-V virtualization software is still necessary to master.  Because it is used both in the program test and in the system training or demo. WW


However, for a production-type virtual server, the main purpose of the snapshot is fault tolerance and catastrophic recovery. If there is a snapshot before the system failure, then the system administrator can use this snapshot to restore the server to the point where the server fails or the problem occurs. Without snapshots, it may take several hours for a system administrator to recover data, even if there is a system backup file. Because not only the operating system and application software need to be restored, but also the important data. With snapshots, the system administrator simply chooses the snapshot before the failure and chooses to start the client image. After the system starts the client image, the virtual server is in the state of the image at the time the snapshot was created.