I can think of a controller that would keep first few GB of sectors addresses and the rest use as a circular buffer for incoming write requests. The stored data doesnt need to be contigous in the physical storage - the controller could store a mapping between the requested address and the actual allocated address, which is not much different from what SSDs already do if I understand things right. This way the partition and filesystem, as well as _last_ few GB of written data (independent of where it was written) will be seemingly preserved, but the rest will be continuously overwritten. I dont think validrive would be able to detect such devices, as it writes a small amount of data for speed, which the driver could very well allocate in such a circular buffer fashion. Only way to detect this would be to write and verify an amount of data that is more than the actual storage in the device. Comments?