Issue #2531 has been updated by swildner.
OK, I've pushed (and MFC'd) a fix that allows turning off APM for disks at least with nata(4). I think in order to have have this for AHCI attached disks too (via camcontrol(8)), we'd have to integrate ATA into CAM like FreeBSD did. But I'm not 100% sure about this. ---------------------------------------- Bug #2531: camcontrol fails to disable APM http://bugs.dragonflybsd.org/issues/2531 Author: m.lombardi85 Status: New Priority: Normal Assignee: Category: Target version: I installed dragonfly BSD on an AMD64 laptop but I have a problem. The hard disk is continuously spinning up and down every few seconds; on FreeBSD I normally execute the following command to disable APM #camcontrol cmd ad0 -c "EF 85 00 00 00 00 00 00 00 00 00 00" but unfortunately it fails on dragonfly with the following error message: camcontrol: error sending command -- You have received this notification because you have either subscribed to it, or are involved in it. To change your notification preferences, please click here: http://bugs.dragonflybsd.org/my/account
