Manually Delete Agent and Targets Using EMCLI in OEM 13c

Although it is recommended to remove targets through OEM console interface, command line utility is more helpful/convenient in some scenarios.

For example, the target host is crashed and cannot be restored, and a new host with new name is built for replacement. Therefore,
the old host and all targets running on this host have to be remove from OEM. Depends on number of targets, it could be a pain to remove
them through console. At this time, manually running EMCLI command becomes the best way.

Following command removed the agent running on server host01 and all targets monitored by this agent,

[oracle@oms1]$ $EMCLI_HOME/bin/emcli login -username=sysman
Enter password :

Login successful
[oracle@oms1]$ $EMCLI_HOME/bin/emcli delete_target -name="host01.dbaplus.ca:3872" -type="oracle_emd" -delete_monitored_targets -async
Target "host01.dbaplus.ca:3872:oracle_emd" deleted successfully
[oracle@oms1]$

We can also run EMCLI command to remove a specific target,

$EMCLI_HOME/bin/emcli delete_target -name="<target-name>" -type="<target-type>"

To remove database (instance)  TESTDB,

$EMCLI_HOME/bin/emcli delete_target -name="TESTDB" -type="oracle_database"

To remove ASM instance target +ASM_host01.dbaplus.ca,

$EMCLI_HOME/bin/emcli delete_target -name="+ASM_host01.dbaplus.ca" -type="osm_instance"

To Oracle listener LISTENER_host01.dbaplus.ca,

$EMCLI_HOME/bin/emcli delete_target -name="LISTENER_host01.dbaplus.ca" -type="oracle_listener"