Thanks Gia.
I was running 10.3.
I followed your instructions with Disk Utility/repair permission, which seemed to 'work' but I did not see anything that indicated SMART status (and I don't know what that means, or perhaps where to look). I also attempted to "repair disk" and that failed...
My problems started with the SBBOD (spinning beach ball of death) and the machine responding/processing sluggishly. (Note: I have plenty of available memory and RAM)
I ran Disc Warrior several times, and each time it repaired problems, but now (2 days later) the machine won't start up, and...