Root mount failed:5

[Matthew Dillon]

    More possibilities after talking to Marino, who had a similar issue
    after a power failure.

    Since it tried to do recovery your machine had clearly crashed or there
    was a power failure.  The question I have is... which was it?  An OS
    crash or a power failure?

    I think there could be an issue with the IDE driver ('ad' attachment)
    being able to issue disk flushes.  If a power failure occurs on an 'ad'
    attachment while the disk is busy it's possible that data wound up
    committed to disk out of order.

    There are other possibilities if it was a power failure, too, but at
    the moment I think it could be the IDE driver or BIOS/chipset
    implementation ignoring the disk flush command.

						-Matt