Summary: Purchased as a replacement for a failed backup server. Came with 3 SATA drives in RAID5 array. Our configuration was 2 SAS Drives in RAID1 mirrored array. Our drives plugged right in to the bays and with NO MANUAL CONFIGURATION - automatically reconfigured and fired right up. Could NOT have gone smoother. Matches the existing equipment exactly yielding us ideal interchangeability. Super product.