StableBit DrivePool - State of the art, file based drive pooling software.
TrueNAS Core - TrueNAS Core (formerly FreeNAS) is a storage operating system strong and robust enough to meet the needs of enterprise level businesses.
Drive Bender - Drive Bender, class leading storage pooling technology
PetaSAN - PetaSAN is an open source Scale-Out SAN solution offering massive scalability and performance.
mhddfs - The driver combines a several mount points into the single one.
Dell EMC UnityVSA - dell-emc-unityvsa-overview-deployment