Transferring the root filesystem to a ramdisk?

[Cordula's Web]

> > > in an attempt to save power on FreeBSD servers, I'm
> > > trying to replace the hdd with a ramdisk. The idea is to:
> >
> > As for powering down the hdd I did find a page for this,
> > but havent had time to play with it yet:
> > http://www.cran.org.uk/bruce/software.php
> 
> there is a port "ataidle" that sets teh IDE drive's internal idle
> timeout timer so it will spin down if you dont use it..

Yes, thank you. ataidle works like a charm.

> as for scsi, you can sent it a spin-down command with camcontrol but I
> forget the actual command..
> (it should be in the scsi .h files)

# camcontrol stop da0
# camcontrol start da0
works for me.

Now, all I need would be a syscall to switch the kernel's notion
of the root device.

Or is there a way to umount root, and remount it on the md drive?

-- 
Cordula's Web. http://www.cordula.ws/