SOLVED Mini-XL+ fans spin up loudly for a few seconds about every 20-25 seconds

[SoonerLater]

I have a ixSystems Mini-XL+ that is less than a year old running FreeNAS-11.3-U5. About every 20-25 seconds, one, some or all of the fans spin up loud enough that it can be heard in the next room. The fan(s) are loud for about two seconds, then then spin down and it's quiet enough again (even if you were right next to it) that you can't hear it at all. This quiet phase lasts about 20-25 seconds, then the fan(s) spin up and the pattern repeats.

What are the most likely causes of this behavior?

What can be done to stop this irritating behavior?

I was getting IPMI errors on FAN 2 and ixSystems replaced it under warranty. But even after replacing FAN 2, I'm still getting intermittent errors on that fan. They look like this:

 

[Moto'Freak]

After having google this issue, I found this thread for my mini+ the exact same issue with Fan2 spinning cycling every 25 seconds. This was due to colder temps in the room and the fan curve was lowering fan speed to below 600rpms and tripping the warning LC issue at 500 rpms threshold. I solved this by either warming the room (yuck) or I had used this in the cmd to lower the CT value to 400rpm and placed in the Init/Shutdown Scripts section.

Code:

ipmitool sensor thresh FAN2 lower 300 400 700

So if this is your issue, this could possible fix it.

 

[SoonerLater]

After having google this issue, I found this thread for my mini+ the exact same issue with Fan2 spinning cycling every 25 seconds. This was due to colder temps in the room and the fan curve was lowering fan speed to below 600rpms and tripping the warning LC issue at 500 rpms threshold. I solved this by either warming the room (yuck) or I had used this in the cmd to lower the CT value to 400rpm and placed in the Init/Shutdown Scripts section.

Code:

ipmitool sensor thresh FAN2 lower 300 400 700

So if this is your issue, this could possible fix it.

Thank you for your reply. I would try it, but I just RMA'd my system back to San Jose for repair or replacement. I've been going back-and-forth with support on this issue (replaced fans twice and motherboard once) and the symptom continues. Eventually they said that wanted it shipped back.

I emailed support your comment, since it's not a solution that they ever suggested. Maybe (probably) that was all that was ever needed. Ugh.

Thank you again.