just to share what i have read, based on "lwn.net surfing": >From the article that started it all: http://lwn.net/Articles/260795/ >From the specs, if u used ioctl() with FIEMAP_EXTENT_HOLE it will keep returning u the next hole. http://lwn.net/Articles/297696/ http://lwn.net/Articles/260803/ http://lwn.net/Articles/332610/ http://lwn.net/Articles/275722/ a few of the articles above have userspace program that shows how to use the primitive FIEMAP_EXTENT_HOLE to identify holes. have fun!! -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ