Dot Hill Systems II 200 FC - Manual (Page 29)

Chapter 1 Product and Architecture Overview 1-9
Specific Integrated Circuit (ASIC) controller chips handle the interconnection between
the controller bus, DRAM memory, and Peripheral Component Interconnect (PCI)
internal buses. They also handle the interface between the on-board 2-Mbyte flash
memory, 32-Kbyte nonvolatile random access memory (NVRAM), RS-232 port chip,
and 10/100 BASE-T Ethernet chip.
The RAID I/O controller module is a multifunction board. I/O controller modules
include Small Form-Factor Pluggable (SFP) ports, SCSI Enclosure Services (SES)
logic, and the RAID controller. The SES logic monitors various temperature
thresholds, fan speed from each fan, voltage status from each power supply, and the
FRU ID.
Each RAID I/O controller module incorporates SES direct-attached Fibre Channel
capability to monitor and maintain enclosure environmental information. The SES
controller chip monitors all internal +12 and +5 voltages, various temperature sensors
located throughout the chassis, and each fan. The SES also controls the front-panel and
back-panel LEDs and the audible alarm. Both the RAID chassis and the expansion
chassis support dual SES failover capabilities for fully redundant event monitoring.
1.2.2 I/O Expansion Modules
The hot-serviceable I/O expansion modules provide four (SANnet II 200 FC array) or
eight (SANnet II 200 SATA array), or six (SANnet II 200 SATA SE array) SFP ports
but do not have battery modules or controllers. I/O expansion modules are used with
I/O controller modules in non-redundant FC arrays, SATA arrays, and SATA SE arrays
and in expansion units and JBODs.
You can connect SANnet II 200 SATA expansion units to SANnet II 200 FC arrays.
However, certain restrictions and limitations apply to mixed Fibre Channel and SATA
environments.
1.2.3 Disk Drives
Each disk drive is mounted in its own sled assembly. Each sled assembly has
electromagnetic interference (EMI) shielding, an insertion and locking mechanism, and
a compression spring for maximum shock and vibration protection.
Each disk drive is slot independent, meaning that once a logical drive has been
initialized, the system can be shut down and the drives can be removed and replaced in
any order. In addition, disk drives are field upgradeable to larger drives without
interruption of service to user applications. The drive firmware is also field
upgradeable, but the firmware upgrade procedure requires interruption of service.