Re: Internal or external hard drives?
I would argue this way-- if a hard drive crash were the only thing you are worried about, then you are right, it is unlikely (but not impossible, as krone6 mentioned) that all three drives would fail on you simultaneously.
If your computer catches a nasty virus, then all three drives will end up infected, and recovering from that could be problematic, if not impossible.
If your machine is hit by a power-spike (read: lightning strike), then you very well could lose all of your data plus backup.
If an airplane falls on your computer, or the family dog sets the house on fire, you will lose all of your data plus backup.
This is why I, personally, have CD or DVD copies of static data like photos and music, and back up my other data to a network drive and a portable drive I keep at work. That's two copies, at least one off-site.
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