extremly hot temperature and slow fan RN 10200

There is no way to increase the fan speed, though some of the work done by the folks running OS6 on older platforms might be relevant.

Perhaps contact support. 44C is a bit warmer than I like to see my disks, but they will likely tell you it is within spec. 76C seems pretty hot.

On (3) it is possible to mount the drives in a linux system. But the real answer is that you need to have backups (even if the temperature was not a concern).

For the brave ones who are not afraid to use SSH:
You can read http://www.readynas.com/forum/viewtopic.php?f=7&t=71587
With this done, my RN104 with 4 discs runs pretty cool. My cpu temp stays around 50 degrees and my discs stay around 40 degrees.
idling the fanspeed is around 900 - 1000 rpm. (room temperatuur around 22 - 23 degrees)
In your tropical climate it will run most likely around 1500 rpm.
You can tweak the low and high temps a bit in the script, to find a compromise between temperature and fan-noise.

The useful posts seem start around here: viewtopic.php?f=7&t=71587&start=15#p414243

dishmagic66 - It would be nice if you put together a clean thread with your script and installation instructions. That would probably make it easier for other folks who need more cooling.

Here is the workaround to control the fan in one topic http://www.readynas.com/forum/viewtopic.php?f=11&t=76184&p=424296#p424296

I have just purchased a RN104 to upgrade from my older ReadyNAS NV+. I first set it up with four 2TB drives and have now one by one through the past week have upgraded it to four 4TB drives. At first I was dismayed to see that the drive temperatures were 45 to 50 C, and the processor was 65 to 70 C. The fan never spun up over 790 RPM. I checked on line and found that these were pretty much standard temperatures. I have a solution where even after 160+ continuous hours of thrashing to rebuild the array and reshape the data as each drive was replaced, my hard drives are running 32 to 35 C, and the processor runs at 43 to 45 C. Now, at idle, the drive temps are holding at 32~33C, and the processor is at 40~42C.

Here is my "fix": I got a 92mm double ball bearing 12VDC fan that moves 56CFM (70,000 hour MTBF which is what, 8 years?) and mounted it on the back of the case with some 3M indoor outdoor double stick foam mounting tape where the built in fan exhausts, and used an old 12VDC power brick from something long gone. No re-programing, no opening the case, no voiding of my warranty. Now I don't care what the built in fan is doing. Many will say this is an inelegant fix, and it may well be, but for $6.0 7 U.S.D. list price for the fan, I will call it a simple solution. My ReadyNAS is set in an area where the noise of this fan doesn't bother me at all. I use it as my whole home media server, streaming mp4 video and mp3 music to 5 or 6 different places throughout the house, which really isn't a strain on the unit. I think the temperatures I have achieved speak for themselves. I hope this helps other people out there who, like me, think that heat is the enemy and leads to hardware failure sooner rather than later!

My RN102 drives are running at 38-40C (100F) without any mods, in a room with ambient temperature of 27C (80F)

What 4 TB drives are you using?