About: http://webisa.webdatacommons.org/131607971

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	I have found that Disk Warrior is the best tool for that but there are others that work well too like TechTool Pro.Try running one of these on your drives and see if it helps.Another thing you can do is have multiple backups.
http://www.w3.org/ns/prov#wasQuotedFrom	cnet.com