You can open Disk Utility and check the S.M.A.R.T status. It will tell you if it's failing or not.
DiskWarrior can repair corrupt OS installs, but it can also tell you via a hardware test if your drive is failing as well.
There are also other S.M.A.R.T tools out there as well. SMARTReporter 2.7.3 is the last free version and SMART Utility (not free) can also give you in depth information about your drive.