It seems that the front fan unit was running at the full speed. The fan itself seems still OK.
I talked with Jamie and make a power cycling (i.e. shutdown gracefully, unplug the power supply cables (x4), plug them in again, and pushed the power button)
The warning signal went off and the fan is quiet. FOR NOW.
Now, daqd and ndsd is down.
FB cannot mount /opt/rtcds and /cvs/cds during its boot.
After mounting these manually, I tried to run /opt/rtcds/caltech/c1/target/fb/start_daqd.inittab and /opt/rtcds/caltech/c1/target/fb/start_nds.inittab
but they don't keep running.
I'll be back to this issue tomorrow with Jamie's help.