If zabbig agentd can't rotate log file, then produce tons message about this and log file growing fastly.

zabbix_agentd_noc [30602]: cannot rename log file [/tmp/zabbix_agentd-noc.log] to [/tmp/zabbix_agentd-noc.log.old]: [1] Operation not permitted
30602:20111121:155437.421 End of send_buffer():SUCCEED
zabbix_agentd_noc [30602]: cannot rename log file [/tmp/zabbix_agentd-noc.log] to [/tmp/zabbix_agentd-noc.log.old]: [1] Operation not permitted
30602:20111121:155437.421 Sleeping for 1 second(s)
zabbix_agentd_noc [30602]: cannot rename log file [/tmp/zabbix_agentd-noc.log] to [/tmp/zabbix_agentd-noc.log.old]: [1] Operation not permitted
30598:20111121:155438.289 In update_cpustats()
zabbix_agentd_noc [30598]: cannot rename log file [/tmp/zabbix_agentd-noc.log] to [/tmp/zabbix_agentd-noc.log.old]: [1] Operation not permitted
30598:20111121:155438.289 End of update_cpustats()
zabbix_agentd_noc [30598]: cannot rename log file [/tmp/zabbix_agentd-noc.log] to [/tmp/zabbix_agentd-noc.log.old]: [1] Operation not permitt