This Hybrid RAID NAS Server was an interesting project. It ties together some interesting piece of hardware that might be useful in other projects. The central piece is the CFI A7879 case (Fig. 1) from E-ITX. It is designed for a Mini-ITX motherboard with room for a full size expansion board. There are four hot swap SATA drive bays (Fig. 2).
The system has actually wound up being a general server that is now central to the lab. It is acting as an Internet gateway, file server and it is running a number of virtual machines. But more about that later.
The CFI A7879 case is stylish and it has a large system cooling fan that moves air across the four removeable drive bays. It has space for a full size expansion board. A two drive version of the case is available.
The motherboard's expansion slot allowed me to take advantage of Adaptec's new Adaptec 6805 SAS controller (Fig. 3). The 6805 handles up to 8 SAS or SATA drives directly and up to 256 drives using SAS expanders. It has a x8 PCI Express Gen 2 interface. There is a 4 port version, the 6405E, but has a x1 PCI Express interface providing a lower throughput. They both provide hybrid RAID 1 support where a solid state drive (SSD) and a hard drive are combined into a single RAID configuration. The Adaptec controller also supports RAID 5, 5EE, 50, 6, 60 and JBOD.
The motherboard for this project is Super Micro Computer's (Supermicro) X9SCV-QV4 Mini-ITX motherboard (Fig. 4). It targets a range of embedded applications from digital signage to 12V automotive. The motherboard can handle the range of Intel Core processors as well as the low cost Celeron B800 series but we packed it with the top end Core i7. This allows the NAS box to do a lot more.
The other main components in the project include Corsair's DDR3 SODIMM, Micron's P300 RealSSD SSD enterprise drives, and Seagate's Barracuda XT SATA hard disk drives. The Corsair SODIMMs are available in sizes up to the 8 Gbytes we used providing the operating systems with 16 Gbytes of memory. The 2.5-in Micron P300 RealSSD drives are SLC flash with a SATA interface. The 3 Tbyte Seagate Barracuda XT drives are 3.5-in SATA hard disks. These were paired in a hybrid RAID 1 configuration.