if vmware cache is full, zabbix server (and probably proxy, too) shuts down and suggests to increase cache size :

please increase VMwareCacheSize configuration parameter

this can be quite surprising when somebody is adding a few vmware hosts in a larger zabbix installation - suddenly it all stops working.

possibly a better solution would be to disable vmware monitoring only.

potential issue - we might have to write this information in item error field, which could cause problems when there are lots of vmware items