I finally got around to shopping for a new hard drive. It's been installed, and now my main workstation is functional again.

I noticed after it was running that I put a 32-bit Ubuntu on it; not a huge problem as Ubuntu has paging to access memory up to 64GB, but performance for that over 4GB is hit, and I think tasks are limited to 4GB which could impact some of the virtual machines. I have prepared a "Live USB" with 64-bit Ubuntu on it, but haven't run through the installer yet.