Wednesday, July 20, 2011

Keeping Virtual Machines at High Speed

Every day, there is more innovation involving the use of virtual machines. For example, development is underway to virtualize user PCs when they are not in use, so that the physical machines can be shut down and power can be saved. In another example, virtual machines have given a considerable boost to cloud computing, and new cloud platforms and cloud system management options are constantly appearing on the horizon. Overall, it is clear that virtual machine technology has blown the door to our future wide open.

From a user standpoint, virtual technology will only become simpler. A few keystrokes and a new virtual machine is launched, complete with an operating system and the applications required for the particular tasks they are needed for. As with all computing technology, however, beneath that simple interface there is much occurring—various resources are being shared and coordinated so that work smoothly occurs across multiple platforms and environments.

The simplicity and speed which virtualization provides, however, can be heavily impacted if several key issues are not addressed.

The basic level of I/O reads and writes is one which can determine the speed of the entire environment. Fragmentation, originally developed to make better use of hard drive space, causes files to be split into thousands or tens of thousands of pieces (fragments). Because many extra I/Os are then required for reading and writing, performance can slow to a crawl, and I/O bandwidth will quickly bottleneck.

Due to the multiple layers that an I/O request must pass through within a virtual environment, fragmentation has even more of an impact that it does in hardware-platform-only circumstances. It can even lead to an inability to launch and run more virtual machines.

In virtual environments, fragmentation cannot be dealt with utilizing a simple defragmentation solution. This is because such a solution does not effectively prioritize I/Os, and shared I/O resources are therefore not coordinated.

A condition also exists within virtual environments that can be referred to as virtual disk “bloat.” This is wasted disk space that occurs when virtual disks are set to dynamically grow but don’t then shrink when users or applications remove data.

All of these issues, fortunately, are answered by a single solution: virtual platform disk optimization technology. Fragmentation itself is dealt with by preventing a majority of it before it even occurs. When files exist in a non-fragmented state, far fewer read and write I/Os are needed to handle them, and speed is vastly improved. Virtual machine production needs are fully taken into account as resources are fully coordinated. Wasted disk space is easily eliminated with a compaction feature.

These basic problems can keep virtual technology from providing the simplicity, speed and considerable savings in resources that it should. They can now all be handled with a single virtual machine optimization solution.

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