For those like me who finds TrueNAS the better choice, just wish it could do spindown properly for home usage, and are willing to tinker with it, here is a patch file of the changes I did to get spindown to work for me:
spindown.patch.txt (3.5 KB)
As with any such things, WARNING:
Doing this is of your own volition and
not supported by IXsystems or me in any way.
You will likely be denied support if you
submit a ticket with these changes applied.
Having said that, if you are familiar with Python, you will see the changes are pretty harmless.
To apply it, put it somewhere in your TN, remove the “.txt” extension, and do these commands in the shell:
cd /
sudo /usr/local/libexec/disable-rootfs-protection
sudo patch --verbose -N -p0 -i /path_to_file/spindown.patch
Must reboot afterwards.
This patch was made for 25.10.0.1
When updating your TN installation in the future, will need to reapply the patch after booting with the new TN version.
FYI, it is not just the temp monitoring that causes problems, there are other issues that either prevents the disks from spinning down, or keeps spinning it up on a frequent basis.
Keeping in mind that if the disks are not spinning for most of the time, the smart monitoring of TrueNAS may not catch any issues.
For me, in the worst case the smart alert check will run at least during the regular zfs scrubs, which is ok to me.