How to change link_power_management_policy and make it persistent?

[serving_myself]

Hello there,

I'd like to enable ALPM for my SATA HDDs by changing the /sys/class/scsi_host/host*/link_power_management_policy from max_performance to med_power_with_dipm or med_power (if the former will result in a degraded pool).
I wasn't able to find a sysctl for this and trying to run midclt call system.advanced.update '{ "kernel_extra_options": "link_power_management_policy=med_power_with_dipm" }' + reboot wasn't fruitful.

I'd use powertop for that, but the old version of it on Scale (from 2019) has this set to min_power, and this was changed later to med_power_with_dipm in this commit:

tuningsysfs: use med_power_with_dipm for SATA link power management · fenrus75/powertop@02703a0

Instead of using min_power, which has reports of data corruption, use med_power_with_dipm (Device Interface Power Management) available since 4.15. This has the same behaviour as the Windows IRST ...

github.com

Could you please let me know what's the best method to do that?

P.S: I'm aware that this was changed to max_performance at some point in Scale because some people's pools became degraded and they had bunch of SATA errors in their logs.
However, based on my research so far I see that these were with slower disks (SMR and/or 5400rpm) which in theory could be at play as well. I can also see that for some people who had issues with med_power_with_dipm, the med_power was just as OK as max_performance.
This is new build w/o any data yet (only TM backup is sent there so far) so I'm willing to test this in my own env for the sake of low(er) power.

 

[serving_myself]

Bump :)

 

[sretalla]

Storage | Disks ... Edit a disk.

Select from the list called "Advanced Power Management".

 

[serving_myself]

Storage | Disks ... Edit a disk.

Select from the list called "Advanced Power Management".

But that's not it, is it?
What you're referring to is HDD APM, and I have it set to "spindown".
This has no effect on the SATA link speed though (what ALPM ultimately controls), and the /sys/class/scsi_host/host*/link_power_management_policy is still set to max_performance in my case (as I'd expect it to be in this case).