vmware collector uses memory more than VMwareCacheSize. It seems that the process has memory leak problem.

StartVmwareCollectors=1
VMwareFrequency=60
VMwareCacheSize=8M

This Zabbix server monitor 1 vSphere 5.1 directly, and 7 VMs are working on the vSphere. vmware collector uses 120MB memory for 3 weeks, and continue to grow.

zabbix 4676 0.0 0.0 141920 2972 ? S Jan15 0:16 /usr/sbin/zabbix_server: ipmi poller #3 [got 0 values in 0.040843 sec, idle 5 sec]
zabbix 4677 0.0 0.0 141928 2524 ? S Jan15 1:55 /usr/sbin/zabbix_server: snmp trapper [processed data in 0.000051 sec, idle 1 sec]
zabbix 4678 0.0 0.0 141920 2960 ? S Jan15 0:16 /usr/sbin/zabbix_server: proxy poller #1 [exchanged data with 0 proxies in 0.000009 sec, idle 5 sec]
zabbix 4679 0.0 0.0 141920 2756 ? S Jan15 1:16 /usr/sbin/zabbix_server: self-monitoring [processed data in 0.000016 sec, idle 1 sec]
zabbix 4680 0.3 3.9 256608 123620 ? S Jan15 71:04 /usr/sbin/zabbix_server: vmware collector #1 [updated 0, removed 0 VMware services in 0.000008 sec, idle 5 sec]