18 Operating Manual RX900 S2
Functional overview
Temperature sensors variably adjust the system fans. If a temperature sensor 
fails or is removed, the system fans affected run at maximum speed so as to 
provide the greatest possible protection for the hardware.
If a system fan fails, unimpaired further operation is ensured. A defective 
system fan module can be replaced during operation, see section "Hot-plug 
fans" on page 106.
High RX900 S2 of availability and data security
When memory data is accessed, 1-bit errors in the main memory are identified 
and automatically corrected with the ECC (Error Correcting Code) method. The 
patented memory scrubbing function regularly starts up the EDC mechanism 
(Error Detection Code) and thus ensures continuous data integrity.
The memory modules support SDDC technology (Chipkill™), which further 
increases the effectiveness of memory error monitoring and correction.
Memory modules can be protected against failure by intra-CPU mirroring for 4 
CPUMEMR configurations and inter-CPU mirroring for 6 or 8 CPUMEMR 
configurations, see "Baseboard D3144, CPUMEMR D3145, PCIR D3146 for 
PRIMERGY RX900 S2 Technical Manual".
ASR&R (Automatic Server Reconfiguration and Restart) restarts the system in 
the event of an error and automatically "hides" the defective system 
components.
The PDA (Prefailure Detection and Analysis) technology from Fujitsu analyzes 
and monitors all components that are critical for system reliability.
The SAS RAID controller supports the RAID levels 0, 1, E1, 5, 6, 10, 50, and 60 
thus increasing system availability and reliability.
Additional reliability is provided by the hot-plug HDD/SSD modules, fans and 
power supply units.