Just wanted to say thank you @mgutt! I had an earlier version of your RAM Disk installed. Wasn't even sure of the version, as it didn't have the version number in the comments. Must have been from a couple of years ago. In any case, after upgrading to 6.11 recently, I noticed that my Disk 1 would have writes to it frequently, which wakes it up along with my two parity disks. This is despite me emptying all contents from Disk 1, and all of my Dockers running from the SSD cache pool. Also, new writes should have gone to the cache pool and not the array. I spent hours watching iotop and dstat, and I was about to pull my hair out when I noticed that Disk 1 would only wake up when certain Docker container is running (specifically DiskSpeed and HomeAssistant). On a whim, I looked to see if there is a newer version of the RAM Disk available, and found this thread. I updated the RAM Disk code, and viola! No more disks waking up! Still not sure why certain Dockers are writing directly to the array or why it's always Disk 1, but I'm glad the new code fixed the issue