I have a few ideas I would like to try out in the Disk Defragmentation Arena. I came to the conclusion that as a precursor to the implementation, it would be useful, to be able to put a disk into a state where it was fragmented. This seems to me to be a state that is more difficult to achieve than a defragmented one. I would assume that the commercial defragmenter companies probably have solved this issue.
So my question…..
How might one go about implementing a fragmenter? What makes sense in the context that it would be used, to test a defragmenter?
How you can best fragement depends on the file system.
In general, concurrently open a large number of files. Opening a file will create a new directory entry but won’t cause a block to be written for that file. But now go through each file in turn, writing one block. This typically will cause the next free block to be consumed, which will lead to all your files being fragmented with regard to each other.
Fragmenting existing files is another matter. Basically, do the same, but do it on a file copy of existing files, doing a delete of the original and rename of copy.