While BTRFS' RAID has issue, BTRFS on RAID can be done. I do something like this, https://kb.synology.com/en-us/DSM/tutorial/What_was_the_RAID_implementation_f

While BTRFS' RAID has issue, BTRFS on RAID can be done. I do something like this, https://kb.synology.com/en-us/DSM/tutorial/What_was_the_RAID_implementation_for_Btrfs_File_System_on_SynologyNAS https://kb.synology.com/en-us/DSM/tutorial/What_was_the_RAID... Basically, mdadm, then on top, format with BTRFS