Well, again, you can't stop a HD From Dieing.
Also, even though you have your data on a separate drive than the one in question you should still have it backed up also.
I may be paranoid, But I have a separate HD with all important DATA backed up onto it. Then I have CD's and DVD's containing the same data. Then I have 2 Flash Drives with some important installation files on them. Then I have more backed up onto my lab top.
Point is, you can never be too redundant. In the rare situation that all your HD's die at the same time you will have the Hard copies to fall back on. (CD's and DVD's)