I’ve had my HL15 since the end of December. It has been completely silent. However, I noticed today that my Noctua fans have been spinning up and down all day. I believe it’s the internal fans behind the hard drives, not the ones on the outside. My system is doing absolutely nothing but idling, but the fans will spin up and then back down. As soon as log into the dashboard, the fans kick on full speed.
I updated TrueNAS Scale to ElectricEel-24.10.2.1 from ElectricEel-24.10.2.0 about 8 hours ago hoping the reboot might resolve the issue, but it didn’t. The CPU temp has been consistently around 40-45. I have 6 drives in here and their temperatures tend to hover around 32.
Any clue as to why the fans have chosen today to run at higher speeds?
What sort of fan curve do you have set in the BIOS or IPMI?
Just to confirm, you just have TrueNAS running as the bare metal OS; not running it as a VM under Proxmox or something? You have no other linux fan control software installed like lm-sensors or fancontrol? And you are sure nothing else is going on like a scrub (when was the last time the system did a scrub)?
Yes, TrueNAS is running on the bare metal and it is a full build with the Noctua upgrade. I’ve been in the room with my HL15 for close to an hour this morning and I still hear the fans rev up every 10 minutes or so. Maybe it’s been going on all along and I just didn’t notice.
Well I don’t have a full build. My understanding of the Noctua upgrade is the fan speed is controlled by the potentiometer in the case and not based on IPMI temperature sensors. So, I’m a bit surprised they aren’t running at some constant speed.
I wonder if this has to do with the “minimum RPM” issue described here;
Although that post is before the Noctua upgrade was available, apparently if a SM board detects the fans are spinning too slow, it believes there to be a failure, so it ramps them up until that clears and the fans spin down again, which cause the “fault” again, over and over. Maybe you just need to adjust the knob a bit so the fans don’t fall below 500 RPM or so? Or try one of the other things mentioned in the thread. I don’t know why this would have just started though.
I think the minimum RPM is a good thing to check. It’s possible that environment has changed just enough with the seasons to put the fans just under the 500 rpm. Also, maybe the fan controller was bumped the last time you were in the case? What do you see in the IPMI Sensors page? The fan controller should be plugged into header FAN1, 2, 3, or 4. Let us know what you find after checking that and the connections. I’m definitely intrigued.
The NA-FC1 Fan controller works this way when not plugged into a fan motherboard fan header with the dial offering 0-100% fixed fan speed. When it’s plugged into a motherboard fan header, the controller switches into a “limit” mode where the dial sets the maximum fan speed but otherwise respects PWM. It also has a “no stop” mode which doesn’t allow fans to turn off but it sets the minimum to 300 RPM. A good feature but its below the 500 RPM noted earlier.