> Plus traditionally a RAID1 of 3 disks will mirror the same data on all disks, which is different to how the RAID1 mode on BTRFS acts. You have raid1c<drive c

> Plus traditionally a RAID1 of 3 disks will mirror the same data on all disks, which is different to how the RAID1 mode on BTRFS acts. You have raid1c<drive count> mode in BTRFS which does this.