Generally when you just delete a file, its contents are marked as "unused", but not actually erased. This is why deleting a large file takes the same time as de

Generally when you just delete a file, its contents are marked as "unused", but not actually erased. This is why deleting a large file takes the same time as deleting a small file. Then, whenever a new file is created, it might be put (partially) on top of the old file, overwriting the old contents for good.