OpManager monitors the system resources using SNMP by default. However, in the absence of SNMP on the devices, the non-SNMP Linux devices can be monitored using CLI, ie., Telnet or SSH.. All the Unix Servers templates have the resource monitors preconfigured. All you will need to do is disable the SNMP monitors associated and select the CLI monitors and associate them to the required devices.
For monitoring the unix servers, make sure either Telnet or SSH is enabled on them.
Steps to configure Telnet/SSH Monitoring
The CLI-based monitors are associated to the device.