I'm quite disappointed. When I converted my old format virtual disk to the new striped format I expected that Time Machine would only backup the stripes that had actually changed. However, the file modification times for all stripes on all drives are changing every day. It looks like the timestamp on all of them is set to the time when I shut down the virtual machine. Is that unavoidable? It would really be helpful to not have to backup all 30GB to capture at most a few 100 megabytes of changes each day.