*This NVR carries twelve hot swappable hard drive bays. Click here to view available hard drives. Key Features of the QNAP VSU-RP-Pro+ VioStor 56ch. The QNAP VSU-RP Pro VioStor NVR (Network Video Recorder) is the high-end 2U chassis network surveillance server which supports high quality. Buy your QNAP VSU-RP-Pro+ from an Authorized QNAP Reseller! Offering free shipping on the leading brands of Network Surveillance Cameras and.