journal commit i/o errors

[Alan Cox]

> There's nothing logged in the logs after the journal commit error because the 
> kernel makes the drive read-only at that point.  Most of the time I'm not able 
> to run anything either - I just get a generic "input/output" error message.  I 
> haven't tried running dmesg when the problem happens; would anything useful 
> come out of that?

Probably yes. It will at least give a good idea of the problem. Without
that its guesswork.

Alan