Synology - Synology Hybrid RAID (SHR) allows you to mix and match drives of different sizes, as well as expand your volume later. Best of all, it is non-proprietary, so you can
Synology Hybrid Raid (SHR) – was ist das?
Adding larger drives using Synology Hybrid RAID SHR2 : r/synology
Nested RAID - Fusion Data Recovery
What is SHR and Should you have a RAID or a Synology Hybrid RAID with your Synology NAS - YouTube
How can 2TB drive give protection for 12TB of data in a SHR (Synology Hybrid RAID)? - Server Fault
SEDNA - PCIe SSD SATA 6G 4 Port Hybrid Raid Adapter with HyoperDuo Hard disk acceleration function
Hybrid RAID Solutions | Microsemi
Synology NAS Data Recovery in Dublin Ireland
RAID 10 Data Recovery Services | Data Recovery Labs
RAID-Disk pools - Huawei Enterprise Support Community