Major Bonehead move:

[Kyle]

Depending on the distribution you are using, you should be able to run its package management software from the install media and specify the top-level directory of the affected drive as the root of the package installation. You should be able to bootstrap a system, only reinstalling the packages you had rather than doing a complete reinstal. Failing this, just go ahead and reinstall the entire system, backing up /home and /etc first, and then copy /home and /etc back to the newly installed system. This way, you shouldn't lose any files or configurations.; you will only need to reinstall any extra packages that are not part of the base install. Hope this helps.
~Kyle