The Tivo can run a complete scandisk of the MFS filesystem and database.

You can manually force a mfs scandisk by telnetting in and running:

mfsassert -please

This will reboot the Tivo and show the green screen "a severe error has occured" - this is normal - it shows this warning because it is usually triggered when the tivo has detected a database error. In this case it was triggered manually by the mfsassert command.

The GSOD will typically take about 20 minutes to complete and the results can be viewed by looking at the kernel log file.

WARNING: The GSOD check uses the swap partition. If you have upgraded to two large drives and not upgraded the swap partition to 127MB then it is possible that the process will not be able to complete. The modern tools and instructions will get it right but you should take a backup before forcing a GSOD just to be safe.