Clearing Settings - Factory Reset Or ??

kd4e

Pulling my weight
Jun 11, 2023
279
131
Nevils, GA USA

Before selling our Empiretech (Dahua?) NVR8CH-8P-2AI NVR it occurs that despite removing the drives - some data may still be stored somewhere.

Is that true and, if so, what's the best way to purge it, please?
I read about factory resets - but that seems drastic and may set up the new owner for a mess.
WDYT?
Thanks.