There is little anyone can tell about anyone about their particular genealogy given just a surname. The name is ***** ***** contraction of the Irish surname Donnelly.
Genealogy is the tracing of one's ancestors one generation at a time, starting with parents, then grandparents, great-grandparents, great-great-grandparents and going on backward. Surnames themselves don't have genealogies, and can originate on different continents in different times, often undergoing many changes in spelling.
Please let me know if you have questions.