where is the persistant data stored? (which files)

Hey,
 
A) Where is the persistant data being stored? (for the MIBs implemented
already by net-snmp)
(I've seen that the usmUserTable is stored in /var/net-snmp/snmpd.conf,
what about the rest)
 
  1) snmpUsmMIB: (Usmstats, ...) -?
  2) snmpVacmMIB ( vacmAccessTable,...)    - ?
  3) snmpNotificaitonMIB (snmpTargetAddrTable, snmpNotifyTable,...) - ?
  4) ...
 
 
 
B) How can I use the .conf files for saving persistant data of my own?
is there an API for this?
 
Thanks,
Erez.