Suddenly Narcoleptic Hard Drive

[Jack Jackson]

Hi,
Suddenly, my hard drive seems to want to sleep every few minutes. I can 
be working on the machine and I'll, for example, click on a link or a 
new piece of mail, and I'll hear the drive spin up (it's a notebook) and 
see the HDD activity light, and it's clear the drive had gone into some 
kind of snooze.

This is brand new behavior. And the usual caveats - I didn't change 
anything or update the kernel or image - apply.

Any ideas how I can

a. Get some useful metrics to track this activity
b. Troubleshoot?

JJ