How many hard drives are required to be installed in the TNAS?

TNAS has multiple models that can be divided into 1 bay, 2 bays, 4 bays, 5 bays and 8 bays in accordance with the maximum number of hard drives loaded. Number of installed hard drives can be determinated based on actual needs of users, and TNAS can be used normally as long as users install at least 1 hard drive. Number of hard drives installed by users can be less than the maximum bay, and can be added later. However, for users who need to use RAID function, RAID should be recreated when adding hard drives. This operation will delete original data on the hard drives, so users need take notice of backup data with caution.