Virtual machine applications such as Parallels, Virtual Pc and VM Ware are becoming increasingly popular as they allow users a number of options that would otherwise be unavailable to them for example a clean system for faster performance or perhaps the ability to test an application in isolation from your main operating system. Sadly the common hard drive is still a factor that needs consideration as fragmentation can cause data problems.
Just like any other software virtual machines still require (unless you have a very specialist setup) to be run from the hard drive, which is still and probably will remain so for many years to come, the slowest part of your system. Drives can be broken in sub parts know as partitions which can then be utilized as a different drive so to speak but hard disk fragmentation is still an issue.
Hard disk fragmentation occurs when files are split in to multiple chunks as they are slotted into spare space on the hard drive. If you are running a solitary OS chances are you have already noticed considerable slow down in your system since purchase. Just imagine two or more OS's running causing the same file fragmentation! Pretty soon your system could come to a grinding halt.
What is more, the premature wear that all of this fragmentation can cause to the hard disk storage can dramatically reduce the useable life of the storage below. Even complex, high performance, RAID arrays can be reduced to a snail like crawl due to high levels of fragmentation. If this problem starts to show itself on a number of the storage devices in any array you could be left with a situation where data recovery is your only option.
Each operating system will have it's own method of dealing with file fragmentation (or not as the case may be). Whilst Mac OS X will automatically defragment a file under the size of 20mb, windows pays scant regard to how badly files are fragmented. Other systems use a variety of different methods to combat the problem.
Defragmentation utilities can take care of this problem, however, running them practically ties up the machine until completion, slowing the machine to a crawl. So what can be done to remove this issue? There are a number of possibilities that can be tried.
Fortunately we are not left to the operating systems alone as there are a number of third party defragmentation applications that are far superior to the inbuilt OS tools. These can be scheduled to run when system usage is very low for example whilst the system is idle or the screen saver is running. As you go defragmentation is my personal choice.
Use separate hard disks for your Virtual Machine software. While this may appear to fly in the face of VM's in the first place, having a robust and business capable solution is in most cases the driving factor. Some astute companies will even have a dedicated hard disk array solely for the purpose of running VM software if there is a business case for it.