Hi Vamshi ,
If host monitoring is not working than there is problem with Diagnostic agent residing on the host .
Kindly check if the agent is in running status , also is it connected & registered with Solman... ?
If not registered than please execute script to complete it -
smdsetup.sh managingconf hostname="FQDN" port:"5<00>04" user:"USER" pwd:"Password"
FQDN = fully qualified domain name of Solman
USER = User id solman admin
Password= Password of solman admin
Regards,
Nash