Resurrecting an old thread.
I recently installed a new Seagate ST4000VX013 4TB SkyHawk HDD in my 7608NI/I2-8P NVR alongside the original Seagate 2TB SV2000 drive.
As per @Andy.A post above I get 0 HDD detected in the HDD Health pages on the NVR.
I'm currently running the latest 76xx firmware...