I have the following graph: http://i45.tinypic.com/flar6f.jpg
I am graphing device memory usage via SNMP. It has an OID for used and free memory but not total. To graph total memory (as it is upgradable) I added the third item (total memory) with no data source and used the CDEF function "Total All Data Sources". As you can see, it hasn't worked.
snmpget both OIDs return Gauge32 values that are the used and free memory in bytes. Cacti seems to be automatically convertering them into Megabytes and Gigbytes so my CDEF item isn't working as expected (it says 1.06GBs of total memory).
How can I correct this, so that the total is 1.08GBs + 607.61MBs?