10
JBOD Controller and Interface
The enclosure is managed by expander controllers that distribute data flow to individual disk
drives and report operating status through a proprietary enclosure service via in-band
protocols. The enclosure, along with other JBODs, connects to a Unified Storage system and
serves as a building block of a scalable configuration.
In terms of supported protocols, the firmware supports communications with enclosure
devices, SAS/SATA disk drives and as Unified Storage system featuring SAS expansion
ports.
In terms of physical connection, the SAS interface provides ease of cabling through Mini-
SAS connectors. With a backplane adapting SAS or SATA drives, the system supports
enterprise-class SAS, Near-line SAS, cost-effective SATA-II or SATA-III hard drives or
SSDs, and is ideal for adding large capacity to a storage pool.
Power supply unit with built-in cooling module
Cooling module is built into the power supply unit (PSU) to protect the system from
overheating. The two hot-swappable PSUs provide constant power to the system. The
modular nature of the system and the easy accessibility to all major components ensure ease
of maintenance.
The Rear Panel
Dual Controller Models
Controller A is located on top and controller B at the bottom for all models. If one controller
fails, the second controller module will take over in a manner that is transparent to
application servers.
2U models
3U models
The top controller (Controller A) is the primary controller. The bottom controller (Controller
B) is the secondary (= redundant) controller which is idle during normal operation and takes
over the management role when Controller A cannot function properly due to hardware
error, controller module removal, etc.
If the failed Controller A restarts or a replacement is installed, Controller A will temporarily
assume the role of the secondary controller.
When the Unified Storage system is rebooted, all system configurations will revert back to
the default state and Controller B returns the primary role to Controller A.
A
B
A
B
