How to check if Postgresql files are OK

Folks,

I was using PostgreSQL 8.x in development environment when one day I
started getting all kinds of low-level errors while running queries and
eventually had to reinstall. Maybe it was salvageable but since it was a
test database anyway it didn't matter.

We use PostgreSQL 9 on our production server and I was wondering if
there there is a way to know when pages get corrupted. I see that there
is some kind of checksum maintained from 9.3 but till then is there a
way to be notified quickly when such a thing happens? I use a
basebackup+rsync of WAL files as a disaster recovery solution. Will this
be useful when such a scenario occurs?

Thanks.