RAID Storage

• Coraid's SATA+RAID EtherDrive Storage Appliance (such as the SR1521) includes a RAID controller within the chassis to allow one or more RAID sets to be accessed as "logical" AoE devices called "LUNs". (ie. LUN 1.1 shown here is a RAID5 made up of 5 disks in slots 0, 1, 2, 3, and 4, and accessed as one large block storage device, such as /dev/etherd/e1.1)
   
• A simple console port command line interface is provided on the Storage Appliance to configure the RAID setup.
   
• Multiple RAID sets can be created within one storage shelf. Combinations of different RAID set types are allowed, including RAID0 (stripe), RAID1 (mirror), RAID10 (stripe of mirrors), and RAID5 (stripe with parity).

RAID5 - write

RAID10 - write

• RAID sets can be expanded with a grow command. This allows RAID sets to be concatenated (when the first RAID set is full, data is stored on the concatenated member RAID set).

RAID10 - grow write 

• RAID sets can be protected with one or more spare disks within the chassis. A single spare disk can protect multiple RAID sets.
   
• The diagrams to the right, show a RAID5 set with a failed disk in slot #1 and a spare disk is available (shown in slot #13), the RAID will automatically rebuild the RAID set using the spare disk. When the failed disk has been replaced, it will typically be assigned as the spare disk.

RAID5-Spare