When Good Disks Go Bad ...........................................................................
Steel yourself for some bad news: Your hard drive will die someday. I can’t
tell you when, where, or how. But I can promise that sooner or later the rav-
ages of time, heat, physical shock, and the laws of physics will result in the
drive grinding to a halt or otherwise failing.Why am I so sure your hard drive will not live forever? Because they are
mechanical devices. They have a motor that spins the platters, an actuator
that moves the read/write heads in and out, and a set of electronics that has
to exist within a sealed box. Add the fact that laptops move from place to
place — sometimes with the hard drive spinning — and you’ve got a melt-
down waiting for just the wrong time and place to happen.Now, mind you, modern hard drives are amazingly robust. With any sort of
luck your drive should last for many years, probably well beyond the obso-
lescence factor for your laptop. But you should always act as if the last time
you shut down the machine is the last time you will be able to use it. Back up,
back up, back up.If you’re lucky, you’ll have some advance warning of an impending hard-drive
death:An occasional hiccup where the drive won’t come to life when you first
apply power but comes back on a reboot.An intermittent warning from the operating system or the BIOS that it
cannot communicate with the drive.
A specific alarm from a disk-monitoring software utility.A steady (or irregular) increase in the number of bad blocks discovered
by a system utility program.Your response to any of these signals should be to double-check your
emergency backup plans for your disk. Don’t ever leave the only copy of
an irreplaceable file on a hard drive, or anywhere else; always make sure
you have backup copies on a CD, another hard drive, or other media.In my system, I make copies of live projects on an external hard drive every
other day — more often if I’ve done a lot of work or have any premonitions of
disaster. And then, in a belt-and-suspenders preventive action, I also burn
CDs with current projects at least once a week. Bottom line: The worst that
can happen on my system is that I lose a day or two’s worth of work. With
CD-Rs costing somewhere between 10 cents and a quarter, they are the
cheapest form of insurance you can get for your data.I’ve already explained how data is stored in concentric circles, called tracks.
Then there are the radiating spokes that extend from the center to the outside,Chapter 7: Easing In to Hard Disks 123