Agreed with Pradeep. However, the best way to be sure the backup is valid is to have tested it against another server in an actual restore. For some of our most vital databases, we have a nightly job that restores them to a staging environment. It does two things. It gives our a developers a place to validate production issues without letting them into the production system, and it validates our backups are good, because we can, and do, restore from them.