Running 6.12.14 from about 5 days ago. Am building the Array from existing HDDs. I have two parity drives and one data drive in the array. And I just added two Disks to the array and Unraid is preparing these two HDDs, aka pre-clear operation is undergoing. 

 

I noticed that the two parity drives and the one data drive don't go spinning down even there is no file activities detected by 'File Activity'. If I manually spin down these drives, they will spin up couple minutes later. 

 

By the way, before adding these two Disks into the array, I have let Unraid run couple hours and HDDs, including parity drives did spin down. 

 

So I think that this is the normal behavior when Unraid id preparing HDDs. Is my understanding correct? 

I assume you mean Unraid is clearing the disks you added to the array. Preclear is something you do outside the array with a plugin to test a disk and also allow it to be added to the array without the need to clear it. 

 

If you have Docker and/or VM Manager enabled without cache or other pools configured for them then that is probably the reason the disks are spun up. 

 

 

Right, I mean Unraid is cleaning the new disks. I do have cache configured for separate nvme drive. I have two dockers running, Plex and duckdns. However, those two dockers were running before the disk cleaning started. Before the disk cleaning started, all drives in array did spin down.

 

Attach Diagnostics to your NEXT post in this thread.

I did further investigation and found out that the symptom is caused by duckdns docker. If I turn duckdns off, all drives will spin down. If I turn duckdns on, couple minutes later, all drives will spin up. Anyone knows why duckdns causes all array drives spin up? Its appata is mapped to /mnt/user/appdata/duckdns which is in cache. Also attached is the system diagnostic. 

server-diagnostics-20241202-2125.zip