You mean they "re-synched" and nothing sunk, hopefully!

Look in /etc/mdadm.conf for the following:

# When used in --follow (aka --monitor) mode, mdadm needs a
# mail address and/or a program.  This can be given with "mailaddr"
# and "program" lines to that monitoring can be started using
#    mdadm --follow --scan & echo $! > /run/mdadm/mon.pid
# If the lines are not found, mdadm will exit quietly
MAILADDR iznogoud at bigpapa
#PROGRAM /usr/sbin/handle-mdadm-events

The last line is something you can build yourself, but I think the monitoring
capability of mdadm running on its own will suffice. You can put it in
/etc/rc.d/rc.local or similar for your distro to launch at booting.

A personal preference of mine for servers I run is to launch services from
the command-line manually when I boot them (does not happen often). I throw
an mdadm --monitor with an 'at now' command. The idea is that if the monitoring
process fails, I will get an email from the cron-job termination. Again, these
are personal preferences and some admins may disagree with my practices.

I really want to find some time to play with Linux md and experiment with
RAID and networked RAID.