What logs etc do I need to checkfrequently?

[Joachim Dagerot]

As you with good memories know, I lost 3000 pictures of my first sons
first year this month. I did have a RAID-5 system with fresh disks,
however, shit happens and I have a feeling that this could have been
avoided if I read my log files better.

So basically, 

a) I get a mail each time my a cron-event fires, this happens every 30
min so the mailbox are quite loaded, not very funny going through.

b) The file messages contained information that my raid-system was
about to blow, I didn't see this because I never read that file. Also
it appears to only log information after a reboot.
The vinum history file seems to only hold information about the vinum
setup, not the health of the volumes.

Questions:

a1) Is it possible to only get a mail with critical information, where
and what do I need to do to achieve this?

b1) Where will information about ongoing disk-problems appear? How can
I see that there is a flaky disk in a non-rebooted system?


In addition to the questions above, is there something else I need to
tune/install/setup/configurare to get a very reliable system that
report critical data to me but where non-critical data is filtered
out?

Thank in advance, my FreeBSD setup is getting more and more mature
now, only thanks to this list.

Regards,
Joachim