Every time I recreate jpstree.jpx it gets fragmented all over the disk in 30 to 40 fragments. I wondered if there is something you could do that would not take too much work to create it contiguously. e.g. write the whole thing in one physical i/o without an aux buffer. write it over top of the existing defragged jpstree.jpx file. It might grow a tad, but that would be just 2 fragments, corrected at the next defrag run. do a dummy write to allocate the max size, then fill in.