Plenty of Free Space on a Disk?
Yes, You Do Need to Defragment
It’s an old myth that still crops up from time to time: if you have a disk with plenty of free space, you don’t need to defragment that disk. This is one of those bits of information that would logically seem to be true. But unfortunately logic has nothing to do with it, and due to the nature of operating and file systems it is completely false.
If you have a disk that is half-full, the files on it are already fragmented just simply due to the way that files are written to a disk. But let’s take a hypothetical situation, and begin with an assumption of a half-full disk with all the files contiguous (each file in one piece). If you leave that disk alone and never write to it again, your free space and your files will remain defragmented. But as soon as you begin opening, saving, closing and deleting files, tiny fragments of free space are created in between existing files, and the file system automatically writes file fragments to those free spaces. Soon, the files on that disk are fragmented, and your performance is just as slow as if you had far less free space.
Additionally you have to consider this: how quickly is that drive going to fill up? It’s an old law of physics that an empty space is a vacuum. Just by virtue of the fact that there is empty space on that drive, you’re very likely going to find data and applications that “need” to reside on that disk. As that disk becomes more full, fragmentation will even more heavily impact performance.
Many sites already know that fragmentation impacts performance regardless of the quantity of data on a drive, and install a defragmenter with every new system they deploy. That way, disk drive performance is never compromised.
An additional mention should be made regarding the specific defragmentation technology in use. The current method, scheduled defragmentation, is no longer sufficient in today’s computing environments. It absorbs valuable computer personnel time to analyze defragmentation on all drives and then to set up schedules for each drive. But more importantly, fragmentation rates are far worse than those of just a few years ago, and scheduled defragmentation is no longer keeping up; fragmentation continues to build and impact performance in between scheduled runs. And in some cases, scheduled defragmentation isn’t even affecting the fragmentation.
Today’s demands require a fully automatic defragmentation solution, one which requires no scheduling and operates transparently in the background utilizing idle system resources whenever they are available.