Greetings!

Are you running the developer version (can you get to shell)? If so, check the /drive0/fids and /drive1/fids directories to see if the files are there. If they are still there, you data is still happy on the drive. If you cannot get to those directories (corrupt, deleted, etc.), then there is a bigger problem.

If the data is there, you might want to try the following possible solutions:

a) manually perform a fsck on the drives
b) grab a boot log, and post for further analysis
c) delete the database and playlist files manually and attempt to rebuild with a sync / reset of player