Unix newbie question - dbsnmp

Just when I was starting to get a bit comfortable with Oracle on NT, I'm told I'll be taking responsibility for some db's on AIX. I know next to nothing about the Unix world (going to a class next week) so am back in the 'newbie' catagory for some things.

Got the book "Oracle DBA Checklists" from O'Reilley. Looks like a handy little reference of things the DBA should do daily, weekly, monthly, etc. and VERY Unix-centric. One of the 'daily' tasks is to check that the DBSNMP process is running. It states that there should be *two* dbsnmp processes running. My question is 'why two?' On NT we only have one dbsnmp service. When I log on to my newly acquired AIX box and do

 ps -ef | grep dbsnmp

it seems to only list one process, though it's still all a bit cryptic to me.

--
Ed Stevens
(Opinions expressed do not necessarily represent those of my employer.)