Defunct Zabbix_Server Processes

Some times Zabbix stops collecting data and all zabbix_server processes are defunct.

Restarting the Zabbix server doesn't fix the defunct processes. According to the manual page (http://www.zabbix.com/documentation/1.8/manual/processes/zabbix_server) on the server config, we can set CacheSize to anywhere between 128K and 1G, the default being 8M. We set it to 32M, and restart the server. Now it's running again. Allegedly, in order to set it any higher, it is necessary to first adjust some kernel parameters with sysctl, like this:

sysctl -w kernel.shmmax=536870912

Or, according to thread 61016 on the Zabbix forum:

Spesific for FreeBSD machine:
kern.ipc.shmall=2097152
kern.ipc.shmmax=2147483648
kern.ipc.shmmni=4096
kern.ipc.semmsl=250
kern.ipc.semmns=32000
kern.ipc.semopm=100
kern.ipc.semmni=128