# NETGRAPH tuning for VIMAGE



## PMc (Apr 14, 2020)

In the past, various people recommended to put the netgraph tuning knobs (net.graph.maxdata, net.graph.recvspace, etc.) to arbitrary high values, but usually didn't have information about why which value would be appropriate.

I am now looking for some more info about these, recommended values etc.

Background: After moving to VIMAGE+NETGRAPH, about once a day I see a `hostname nor servname provided, or not known` from inside an application (about one of thousand nameserver requests). Since the nameserver is on the same hardware, the hostname to resolve is also local, and the logs indicate that getaddrinfo() returns immediately (no timeout), this can only indicate a failure to send. And I have indication that the cause might be the same as in the linked post: `sendto: no buffer space available`. 
But what I definitely do not have is (spare) memory, so it doesn't seem fit to simply push these values to very high values.


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