On top of what the other poster said, I'm wondering if you're not
getting any kind of "postmaster not cleanly shutdown, recovery
initiated or something like that when you first start it up. You
don't tend to see a lot of messages after that until recovery is
completed.
What does top and / or vmstat or other system monitoring tools say
about activity? I'm guessing you just need more patience while pgsql
recovers from the unclean shutdown. But it could be something more.
Hard to say with what you've told us so far.