You should never have to create a data source manually, data sources are based off of data templates. If creating the Graph is not creating it for you, then that needs to be figured out and addressed (most likely a graph template / data template issue).
Without a valid use case, the effort to put it back in is super low on priority.
Generally I would agree with your statement, but I am into a situation where I would need to have a graph template populated by 3 SNMP GET data inputs manually inserted, the use case is simple:
- Cisco QoS input/output bandwidth and drop graphs.
I know there are several scripts doing it but unfortunately there is no match in terms of performance for a single SNMP Get, and we have lots of routers in our network.
I am currently able to achieve my goal with custom data source creation, but I believe you are right an it would be better to fill these info out of a data template to a graph template, but I tried adding 3 SNMP GET data inputs in a data template and unfortunately only 1 OID insertion is requested, rendering the excercise useless.
my thread about this topic : jhonnyx @ [Cacti 1.0.6] Graph template from custom SNMP get OIDs