Laptop mode for FreeBSD

[Richard Lupton]

Hello,

I have an old NEC Versa LX laptop with a very noisy disk. Mostly from
the point of view of making it quieter, rather than saving power, I
would like to let the disk spin down in the same way as laptop_mode
does for linux.
I can set the standby time and power saving options for the disk using
ataidle, but the disk doesn't stay spun down for any length of time.
Does anyone know of an equivalent to laptop_mode, or alternatively the
appropriate sysctls to postpone disk access?

Thanks,
    Richard