Advice from Continu an online back up service
Reliability. Up to 71% of restores from tape contain failures.
Best Practice: Use disk-to-disk technology for backups. With disk-to-disk technology, your backup data resides on disk drives, proven to be far more reliable than tapes. When your backup completes, you know the data is secure and accessible on the disk drive. With tapes you never really know if your data is usable until you try to restore it, at which point it’s too late.