Seagate IronWolf Pro 4TB NAS Internal Hard Drive HDD – 3.5 Inch SATA 6GB/S 7200 RPM 128MB Cache for Raid Network Attached Storage, Data Recovery Rescue Service (ST4000NE0025) : Electronics
Western Digital 14TB WD Red Pro NAS Internal Hard Drive HDD - 7200 RPM, SATA 6 Gb/s, CMR, 512 MB Cache, 3.5" - WD141KFGX : Electronics
🩺 How to Recover Lost Data From 4K Native (4Kn) Drives in 2021 💽 - YouTube
One Volume warning (I/O errors), the other failing (Bad sector) | Synology Community