So how should you make decisions about virtualization? Virtualization should be thought of as hardware abstraction as that is truly what it is, in a practical sense. Virtualization encapsulates the hardware and presents a predictable, pristine hardware set to guest operating systems.
This may sound like it adds complication but, in reality, it actually simplifies a lot of things both for the makers of operating systems and drivers as well as for IT practitioners designing systems. It is because computers, computer peripherals, and operating systems are such complex beasts that this additional layer actually ends up removing complexity from the system by creating standard interfaces. From standardization comes simplicity.
This exact same concept of presenting a standard, virtual machine to a software layer exists in other areas of computing as well, such as with how many programming languages are implemented. This is a very mature and reliable computing model. Hardware abstraction and the stability that it brings are reason enough to standardize on virtualization across the board but the practical nature of hardware abstraction as implemented by all enterprise virtualization products available to us today brings us even more important features.
To be sure, most benefits of virtualization can be found in some other way but rarely as completely, reliably, simply, or freely as from virtualization.
The biggest set of additional features typically come from the abstraction of storage and memory allowing for the ability to snapshot storage or even the entire running state of a virtual machine, that is to take an image of the running system and store it in a file.
This ability leads to many very important capabilities such as the ability to take a system snapshot before installing new software, changing configurations or patching, which allows for extremely rapid rollbacks should anything go wrong.
This seemingly minor feature can lead to big peace of mind and overall system reliability. It also makes testing of features and rolling back or repeated testing very easy in non-production environments.
This allows for operating system agnostic backup mechanisms and backups that include the entire system storage pool all at once.
Image backups allow for what were traditionally known as bare metal restores, which allow you to restore the entire system to a fully running state without additional interaction easily and very quickly.
When available, image-based backups allow for extremely rapid recovery at speeds unthinkable with other backup methodologies. Restoring systems in minutes is possible, from disaster to recovery! The ability to treat virtual machines as files at least when not actively running provides additional benefits that are related to the backup benefits listed above.
Namely the ability to rapidly and easily migrate between physical hosts and even to move between disparate hardware. Traditionally, hardware upgrades or replacements meant a complicated migration process fraught with peril. With modern virtualization, moving from existing hardware to new hardware can be a reliable, non-destructive process with safe fallback options and little or possibly even zero downtime!
Tasks that are uncommon but were very risky in the past can often become trivial today. Often this is the true benefit of virtualization and abstraction mechanisms. Which method is best? That largely depends on the network administrator's needs. If the administrator's physical servers all run on the same operating system, then an OS-level approach might work best.
OS-level systems tend to be faster and more efficient than other methods. On the other hand, if the administrator is running servers on several different operating systems, para-virtualization might be a better choice. One potential drawback for para-virtualization systems is support -- the technique is relatively new and only a few companies offer para-virtualization software. More companies support full virtualization, but interest in para-virtualization is growing and may replace full virtualization in time.
The benefits of server virtualization can be so enticing that it's easy to forget that the technique isn't without its share of limitations.
It's important for a network administrator to research server virtualization and his or her own network's architecture and needs before attempting to engineer a solution. For servers dedicated to applications with high demands on processing power, virtualization isn't a good choice.
That's because virtualization essentially divides the server 's processing power up among the virtual servers. When the server's processing power can't meet application demands, everything slows down. Tasks that shouldn't take very long to complete might last hours.
Worse, it's possible that the system could crash if the server can't meet processing demands. Network administrators should take a close look at CPU usage before dividing a physical server into multiple virtual machines.
It's also unwise to overload a server's CPU by creating too many virtual servers on one physical machine. The more virtual machines a physical server must support, the less processing power each server can receive.
In addition, there's a limited amount of disk space on physical servers. Too many virtual servers could impact the server's ability to store data. Another limitation is migration. Right now, it's only possible to migrate a virtual server from one physical machine to another if both physical machines use the same manufacturer's processor.
If a network uses one server that runs on an Intel processor and another that uses an AMD processor, it's impossible to port a virtual server from one physical machine to the other. Why would an administrator want to migrate a virtual server in the first place? If a physical server requires maintenance, porting the virtual servers over to other machines can reduce the amount of application downtime. If migration isn't an option, then all the applications running on the virtual servers hosted on the physical machine will be unavailable during maintenance.
Many companies are investing in server virtualization despite its limitations. As server virtualization technology advances, the need for huge data centers could decline. Server power consumption and heat output could also decrease, making server utilization not only financially attractive, but also a green initiative. As networks use servers closer to their full potential, we could see larger, more efficient computer networks.
It's not an exaggeration to say that virtual servers could lead to a complete revolution in the computing industry. We'll just have to wait and see. To learn more about server virtualization and other topics, serve yourself a heaping helping of links from the next page. It's possible that much of our everyday computing needs will be handled across a network connection as virtual servers provide applications and storage. As a result, the consumer hardware market could change. You wouldn't need the fastest PC to run the latest software.
A remote network of virtual servers could handle the processing, and all you would need is a simple networked terminal to access it. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots. Mobile Newsletter chat avatar. Mobile Newsletter chat subscribe. Computer Hardware.
How Server Virtualization Works. Virtual Hardware. Why Use Server Virtualization There are many reasons companies and organizations are investing in server virtualization. Some of the reasons are financially motivated, while others address technical concerns: Server virtualization conserves space through consolidation. This innovation has been revolutionary for data centers, as virtualization software allows administrators to essentially multiply their available computing environments.
There are plenty of other benefits to virtual hardware, but here are a few of the top advantages. Data centers contain numerous physical servers that are dedicated to handling the workload from a network. Virtualization allows you to reduce the number of physical servers you need to run your business. Installing a physical server is a long, arduous, and expensive process.
First, you have to order the server, followed by waiting for the hardware to arrive. Server virtualization allows you to clone a virtual machine within minutes without costs. Because each physical server takes up a certain amount of space, there are only so many you can own. Although they still need a physical server to be on, virtual environments only take up virtual space. This means you can multiply the number of available servers you have without needing to create extra space.
To prevent overheating, servers need to be cooled. A lower number of servers also means there are fewer machines that need power. The greatest benefit of server virtualization is convenience.
The convenience of this technology presents itself in various ways, one of the most important being that it improves disaster recovery. A virtual machine can be moved quickly from one server to another.
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