> > I feel that the fact that
> >
> > WAL can't help in the event of disk errors
> >
> > is often overlooked.
>
> This is true in general. But, nevertheless, WAL can be written to
> protect against predictable disk errors, when possible. Failing to
> write a couple of disk blocks when the system crashes is a reasonably
> predictable disk error. WAL should ideally be written to work
> correctly in that situation.
But what can be done if fsync returns before pages flushed?
Vadim