freenas no buffer space available problem and solution

gistfile1.txt

Installed a new FreeNAS and I wanted to apply my usual 10Gbit network tunables.

It turns out it matters a lot in which order you apply them - if you apply them in the wrong order your 
system stops responding and loses network capabilities.

I added net.inet.tcp.sendspace with a value of 4194304 and seconds after my system stopped responding and when logging onto the console 
- I got messages from all network usage no buffer space available

So I looked at the tunables I added with sysctl -a

And I more guesses than knew that my tunable had fucked it up.

So I reset it back to the default 64k and I could restart nginx/django and my interface worked again.

It turns out that before changing net.inet.tcp.sendspace you need to change kern.ipc.maxsockbuf - 
which I had in my other freenas setup - I had apparently just been "lucky" with the order I added them on the other servers.

So I added kern.ipc.maxsockbuf=33554432 - and I could add all the rest of my tunables also the one that fucked it up earlier.