Pr4100 fan control?


is there a fan control on the pr4100?

My drives are around 42C. The fan is still at 540rpm. When will it go up? Whats the fan curve like? Can we manually adjust it?


Just try to put some load on your system, e.g. by transcoding some videos… you’ll hear the fan eventually.

Don’t want to bump this topic but @Tfl can you provide a newbie / clearer version for fan control on the WD PR4100? I did see what you posted in another thread about coding it in, but couldn’t make sense of it since there was so much going on in that topic…if you could help with this would greatly appreciate it.

Reason for it: I replaced the PR4100 stock fan with a Noctua NF-A12x25 PWM fan, which is naturally very quiet, even at slightly higher RPMs, especially compared to the stock fan. The drive had to be put into an AV cabinet (lower shelf, as heat rises and cold air drops), which has 4 fans attached to it to bring in cold air flow and exhaust hot air out for the NAS and two other devices. However, I had to attach 2 additional USB fans for the front and side of the NAS (this was with the stock fan and the Noctua) to maintain lower temps. Currently on a full day at idle it sticks to an average of 36 degrees Celsius, the change of fans didn’t improve anything except lower the RPM, and I still have to use the other two USB fans to ensure it stays at 36. I think it would benefit the NAS being at a slightly higher RPM at lower temps to maintain those lower temps at idle (if that makes any sense).

You can interact with it via serial port.
Here’s a simple script I wrote for FreeNAS.
There’s an more extensive tool written by Michael Roland in, which you can use if you run Ubuntu or Debian.

The stock OS3/OS5 is managed by the fan_control tool.
When you kill it, you have the /dev/ttyS2 all for yourself.
@dswv42 made a nice list of all available commands in his mega info thread.

This is as far as my support goes. Good luck.

Do this at your own risk

@dswv42 hoping you could point me in the right direction on how to get started? I’ve tried finding the list that @Tfl said but can’t seem to trace it back to you. I might also need to emphasise that I am a complete newbie at stuff like this. Only have Mac and Windows systems at home and pretty much have no clue on how to configure this to gain access to the fans. If you can please help that would be greatly appreciated.

Sorry, there’s plenty of info here on the forum but we won’t hold your hand.
I recommend you stick to the stock version of fan control.

Hold my hand? Nice response mate…will just learn it myself if you want to respond like that.

I don’t know what’s worse, speaking to WD support, or when they recommend getting support from the “community” to only get a response like that.

@dswv42 thank you for all the information.

All my files are stored on the 4x 8TB WD Red drives in RAID 10 (that was in the PR4100). I did see on a old post that installing Deb may cause data loss, so removing the original drives and replacing them with one HDD in bay 1 is recommended. If i don’t use a separate HDD, will data loss be the case or is it just a rare chance that would happen? Or should/can I add a partition to the RAID set up, so I can install Deb? Also is it possible that I can still use the WD My Cloud web interface (as I did see that this isn’t possible after installation).

Long story short: I just want to increase the RPM to at least 1000 RPM permanently, where it won’t wipe off when the PR4100 is on a automatic power schedule that turns off during the night.

Yeah I’m probably not going to use that script XD but the first bit of info about Fan Speed (FAN) is probably what I am going to need?

Well mate. I’m all ears and willing to learn, if you are willing to help or can provide help with a direct message let me know. If you need my contact details I can pass it on to you.