I want to create memory graph on cacti. But I have 2 OID for this, used memory (with OID) free memory (with OID). I want to create a graph which function for CDEF used to be (used_mem /(used_mem +free_mem))*100. I mean I want to see on this graph used memory percent on used+free memory. How can I do this? I try to create two data source for one data template but I couldn't use OID's.
I solve this problem with using solution above;