What nationality is the surname Pirzada?

Pirzada is Persian for "son of a holy man". "Pir" = "holy man" and "zada" = "son of". It's a surname used by Muslims in Pakistan and may also be spelled "Peerzada". It may also be used by Iranians. The name does not necessarily mean that the person in question is the son of a "pir" but the lineage might be able to trace back to somene who once was.