same issue with agents on some hosts with rhel 7.1
[root@sec0006li secadm]# ulimit -a
core file size (blocks, -c) 0
sysctl -a | grep -i fs.suid_dumpable
fs.suid_dumpable = 0
still agent refuses to start
17091:20160316:150928.330 using configuration file: /etc/zabbix/zabbix_agentd.conf
17091:20160316:150928.330 cannot disable core dump, exiting...
Red Hat Enterprise Linux Server release 7.1 (Maipo)
This IMHO is wrong !
if clients also demand to disable core dumps ...
This is not a choice that should be made by Zabbix
a warning that coredumps can have performance impact ok
but disabling this on the client side imho not done ...