昨天學校的第二電力中心停電，因為UPS只能撐個兩小時左右，只好把機器給關掉，到了下午五點半左右，學校恢復供電，把實驗打開，發現Cacti無法抓到我實驗機的監控數據。 發現實驗機上的snmpd 沒有在執行，下指令啟動snmpd

% /usr/local/etc/rc.d/snmpd start Starting snmpd. 
Turning on AgentX master support.

就是「Turning on AgentX master support.」這個message，是說要開啟AgentX master

一開始先Google這個訊息，發現沒有類似情況，檢查設定檔

% vi /usr/local/share/snmp/snmpd.conf

###########################################################################

# SECTION: Agent Operating Mode

#

#   This section defines how the agent will operate when it

#   is running.

# master: Should the agent operate as a master agent or not.

#   Currently, the only supported master agent type for this token

#   is "agentx".

#

#   arguments: (on|yes|agentx|all|off|no)

master          agentx  on

設定成master     agentx    on就好了