There are several situations in which a DBAN failure could go unnoticed:
- DBAN may fail to detect a hard disk in a computer with many hard disks. You must check whether DBAN actually detected all hard disks in a computer.
- Your hardware caches writes or otherwise does not implement a functional write barrier. This is likely to happen with battery-backed large-memory RAID controllers or defective hard disks.
- Somebody with a lot of time, money, and brains needs to recover your data.
- The software that you downloaded could be bugged or trojaned. (Did you check the PGP signature?)
Users should be aware that there are professional wiping solutions that do guarantee 100% data sanitization of all your IT assets. These solutions are completely secure and well trusted. Once erased, the data cannot be recovered with any existing technology.