【Regarding Hard Drive Capacity Limits】
The per-drive capacity is consistent across the HS series and CS series. It is generally recommended that users employ NAS Red Drives > Enterprise-grade Hard Drives > Surveillance Drives (adapted for 7x24 operation). Using older hard drives in the NAS is not recommended, as prolonged operation carries the risk of drive failure.
【Supported Hard Drive Types】
SATA mechanical hard drives (HDDs) and SATA solid-state drives (SSDs) are supported, as well as M.2 drives. SAS hard drives are not supported.
【Will adding a new hard drive to a NAS require formatting the existing hard drives that have been used for data storage on the NAS?】
The newly added hard drive will be formatted, but the data on the existing hard drives in the NAS will not be affected. You need to select Group Expansion, which will not disrupt the existing RAID array (e.g., RAID 0, RAID 5, RAID 6).
To expand the RAID array by adding a new hard drive, select the corresponding RAID storage pool and choose the newly installed hard drive for Group Expansion. (Note: The feature to add a hard drive with existing data to a RAID array without data loss is still under development. Stay tuned for updates.)