Laptop harddisk power management in OpenSolaris

29 10 2008
If you've installed some flavor of (Open)Solaris in your laptop, you'd probably noticed your harddisk becomes a lot noisy. This is because, at this time, the ata driver that comes with Solaris kernel (even in recent nevada builds) is not able to change the configuration of the harddisk internal APM, which runs in its default configuration and makes it to park its heads every time it comes idle.

To fix this issue, you have two options:

- Download your harddisk's manufacturer tools, which probably can help you to totally disable the APM feature.
- Replace your ata driver with this one: ata-apmdisable.tgz (x86 only). I've added a new ioctl to be able to disable APM on your harddisk at your desire. There you'll also find an utility "powerata" which makes use of this ioctl.

I've contacted the OpenSolaris guys to find a way to get this into Nevada's code, but that can take some time.