If LaCie RAID Manager isn't detecting your device, please follow the instructions here to update your firmware.
*IMPORTANT! 5big and 8big Thunderbolt 2 products require the latest RAID firmware on Intel-based Macs. IMPORTANT: It is strongly recommended to avoid RAID rebuilds on Apple Silicon Mac computers with 12big Thunderbolt 3. Y es (Intel-based Macs see here for M1 Macs) Yes (Intel-based Macs see here for M1 Macs)