Well, this might prove to be the worst night-mare for some of you long-time Ubuntu users.
My laptop has been running on Ubuntu (Hardy Heron ) for around 3-4 months. Ever since then, I’ve been ignoring an unusual noise coming from my harddisk , taking it to be the normal noise for any harddisk. But finally, I decided to google upon it, and what I found scared the hell out of me. In some cases (not all), the noise that is coming is coming due to frequent physical collision of the read/write head of your harddrive with the disc. This happens whenever the read/write head of your harddrive is parking itself more times than it should do optimally.
If you dont know about Parking, then Parking is a process by which your harddrive tries to save power. Usually, the read/write head is always roaming over the rotating metal disks, whenever the harddrive is in use. But when it is idle, the heads are “parked” or moved to a “parking place” present in the harddisk, where it can rest till they’re in need of use again. This saves power but decreases performance.
So If you’re dying to save power and you’re ready to compromise performace for that, then you should want your rw-heads to be parked whenever they finish their job. But as you know, when your computer is ON and you’re using it, then the harddisk gets very little time to rest. This is because almost every action of yours like listening to music,surfing the net,gaming,etc and other heavy-weight applications, requires harddisk for storing cache, temporary data and accessing & updating their core drivers, etc.
Even when you’re not using your computer, most of the time many other activites are going inside it, which are all scheduled using cron/anacron/etc. And if you have configured for “maximum power conservation”, then this means that you’re rw-heads are parked, then again unparked to do some job, then parked again, and again and again. And this means “frequent” collisions of your rw-heads with the discs which happens during every parking/unparking.
All this happens when the default configuration in Ubuntu harddisk driver isn’t compatible with the type of harddisk you use. The another possible reason is that your harddrive , is indeed already faulty. But If it’s not, then it is on its way of becoming one.