SOLVED : CONCLUSION :
my feb25th hypothesis was correct
The command "btrfs filesystem show 32f96308-aa9a-4c86-b799-d222f4af4a75" was causing all disks to spinup because it couldn't find the UUID requested. That command was issued by /usr/local/emhttp/plugins/dynamix/scripts/monitor that took that information from the "/var/local/emhttp/disks.ini" file that probably gets populated from the files in this directory /boot/config/
The dynamix monitor is called every minute from a cron job in "/etc/cron.d/root"
The UUID in the config file in /boot/config/pools/ are left empty, why? That would be my question. In my case, my older pool config had an uuid that became invalid (or always have been I don't know) when the array failed due to bad ram and I reformatted 1 of the 2mirror drive in that pool and removed the other drive. That UUID was left in the config file of the pool. When I removed that uuid, the monitor script stopped waking all disk every minutes.
It is my understanding that unraid created that problem somewhere during one of those manipulation because I have never played with any of those files prior to this investigation 🔍
Proposition 1 to unraid
Look at what happens when you create a pool array with 2 devices. remove one device, reformat the other one and look at the UUID in the config file. (I can't recreate that, I don't have unused disk right now) Why is there not UUID in the btrfs pool config file? Why did I have one before but not my new one. Was there a changes in the code from previous versions?
Also look for other cases that can create that type of wrong UUID, there might be more that just mine.
Proposition 2 to unraid
The monitor script also fails to recognized the error and send a notification regarding that error.
if (exec("/sbin/btrfs filesystem show "._var($disk,'uuid')." 2>/dev/null|grep -c 'missing'")>0) {
we can see here that it only looks for 'missing' but when a filesystem is not found, it actually return ERROR:
ERROR: not a valid btrfs filesystem: 6790d0c5-bc2f-499f-a9cb-5b5bf6f03d0z
This should be changed to 'ERROR'
But since this script execute every minute, and the next section creates a warning on an error notification. it could potentially flood an unraid admin with warning email. Which could be too much.
(I wish I could create a pullrequest, but I couldn't find the repo on github, the only one I found was 8years old and the code did not match the one in unraid current release)
However, proposition1 has to be implemented first, otherwise, a lot of users might get wrong warnings.
notes:
@foo_fighter
do you use the unassigned plugin? if so, I suggest you update it. This is in the changelog
>Fix: Zpool operation that kept disks from spinning down.
Thank you
Thank you everyone that took a look at my thread and for help and guidance along my route.
finally
Big hurray to me, I have very very basic knowledge of any of this. So congrats to me for finding it. It can potentially affect a lot of users. Please unraid acknowledge in this thread that something will be done.
