Mark M
wrote in message ...

I would guess that the failure curve of a hard drive is much like
that for a lot of electronic equipment. It is probably a sort of
wonky "U" shape.

If it fails then the drive is likely to fail quite early on in its
life. After it passes this period then it is more likely to fail
after some years as it gets older.

Does anybody know approximately how long this period is of relatively
high risk of early failure? This must vary from one model of hard
drive to another but, very approximately, after what period of time
would it be?

I may be wrong but I would guess there is a bit of a "knee" in the
shape of the reliability curve where the risk of failure changes.

If I get a new ATA/IDE hard drive I don't like to use it for live
data until it has been running on test for a while. But how long is
sensible for this test period?

At a usage pattern of 10 hours a day for the hard drive, would this
period be three or four days? A week? Three weeks?

The short story is that while that bathtub effect is certainly seen,
it isnt a lot of use for a particular new drive, even if you have the
full stats the manufacturer has for that particular model, with one
they have been producing for a few months etc.

You've basically just got to recognise that the risk is unquantifiable
higher and that you should be fully backed up anyway with the stuff
you'll slash your wrists if you lose, because you might be the sucker
that ends up with the 1 failure in 10K that fangs you on the arse etc.

Fortunately hard drives are now so cheap that you can afford
to have full backups of what is essential, and full image backups
or RAID for convenience on hard drive infant mortality too.

You should also consider running continuous
protection like PowerQuest's V2i Protector.