Should one enable link power management (not ALPM) for FreeNAS?

[baniero]

Hi everyone!

I have seen that in the bios there is a setting called "SATA AHCI LPM" (Link Power Management) and I am unsure if that should be enabled. From what I have read on the forums ALPM (Agressive Link Power Management) is not recommended. But what about the "normal" LPM?

Thanks!

 

[pschatz100]

According to some posts in found on the web, this setting, when enabled, spins down the SATA drives when they become idle. It this overrules any setting in the HDD firmware or OS. According to the same posters, it may have cause the premature deaths of some older drives because of constant spinning up and spinning down.

I would not use it.

 

[baniero]

Thanks for the quick reply! I read that too but thought that might only apply to Agressive Link Power Management (ALPM).

Also, does the field in FreeNAS "Adv. Power Management: DISABLED" (under storage and then the disk details) refer to this?

 

[Samuel Tai]

Thanks for the quick reply! I read that too but thought that might only apply to Agressive Link Power Management (ALPM).

Also, does the field in FreeNAS "Adv. Power Management: DISABLED" (under storage and then the disk details) refer to this?

No, that's APM on the disk itself, not on the SATA link. It basically controls disk spin-down.

 

[pschatz100]

Advanced Power Management in FreeNAS refers to the profiles that FreeNAS supports. ALPM and LPM refer to power management profiles that your motherboard hardware provides. You don't want two different systems running power management - I would always disable power management on the motherboard.

As to whether or not you want to enable FreeNAS power management will depend upon your specific situation. Some people like to spin down the disks when the system is not being used while others always keep the disks spinning - the argument being that spinning disks up and down too often will shorten their life. I fall into this latter group because idle disks - even while still running - do not draw much power.

By default, FreeNAS does not enable power management. You can read more about this in the documentation.

 

[baniero]

OK, thanks for the clarification everyone! I will go with your recommendation of keeping LPM off then!