kern.ipc.nmbclusters limit reached makes a server go down, please help

[Stefan Stere]

Hi,

I have a vmware virtual server running FreeBSD 10.0 STABLE
The virtual server has 100mbps port.

It is running a Tor router, consuming an average of 6-7 TB of monthly traffic. Its the only purpose of the server.

Last night it went down, and vmware console log was saying:
[zone: Mbuf_cluster] kern.ipc.nmbclusters limit reached


I don't know what this means - the traffic of the server is unlimited and nothing is capped in any way. What can I do to fix this? I have read on freebsd wiki that I might need to add some lines to sysctl ? can you please confirm? Thank you in advance.