By Josh Kern
In a previous blog post, I discussed virtualization and its benefits. Hardware cost reduction and server resource efficiency are the biggest selling points, but there are many other added benefits to a virtual environment. While costs can be reduced due to less hardware needs, there are many disaster recovery points that will help to save on downtime and increase productivity.
In both the Microsoft and VMWare environments, there is a tool called V-Motion. If more than one virtual server exists in this environment, a virtual machine can be V-Motioned to another server. This point can throw many individuals off once they hear it. To create a better understanding, we will discuss an imaginary environment and explore V-Motion a little further.
Example: The firm has 4 virtual servers. Each virtual server starts with VServer and is numbered accordingly (VServer1, VServer2, VServer3 and VServer4). VServer2 needs to have several parts replaced and contains approximately 10 virtual machines. With V-Motion, these 10 virtual machines can be transferred to any of the other 3 virtual servers without having to power down the virtual machines. This process can be related to a copy and paste between two machines. Once all the virtual machines have been transferred from VServer2 over to their temporary homes, VServer2 can be shut down without affecting the other 3 virtual servers.
Depending on how the virtual environment is configured, it is possible to fully recover a virtual machine in the event a virtual server goes down in minutes instead of hours. As an example: VServer2 crashes and cannot be brought back online. By opening the console of a server, the administrator browses to where the virtual machine files are located and reattaches them to one of the operational VServers. This enables the virtual machine to be brought back online without having to do a restore or installing a new server from scratch. If this were to happen to a physical machine, another physical machine would have to be put in its place and the files would have to be restored to get the services back online.
One question commonly asked when explaining a virtual environment is, “How do I use a keyboard and mouse when attempting to attach to the virtual machine if there are so many in one physical server?” Quite simply there is a program that allows for users to view virtual machines and open consoles to them (very similarly to a word processor opening a word processing document). Once connected to the machine, resources can be assigned from the connected workstation (such as CD drives, floppy drives, etc.) to allow for installations or just to the keyboard for log in, typing, etc.
Another advantage of virtualization is that virtual servers do not have a problem in a mixed operating system environment on one physical virtual server. Therefore, you can place a Linux system on the same virtual server as a Windows system and they both will still function without any thought for compatibility issues.
Our firm knows firsthand the benefits of virtualization. As we have continued to grow, virtualization has been able to provide us with faster repairs, longer up times, and overall reduction of cost due to less hardware needs. Since virtualization is a comprehensive set of products that cannot fully be explained in a few paragraphs, I hope I’ve scratched the surface enough to give you a better understanding of the benefits as well as the overall importance of virtualization in a server environment.