I have two Red Hat 6.X servers that drop from OpManager about every week or two weeks. OpManager sees the servers as up because they are available via ICMP but not via SNMP. If I perform a rediscover there is no change, no SNMP data (memory, disk, process, etc.) is available. The only way to get the systems fully available via OpManager is to delete them and then add them back. I've verified that SNMP is setup properly on the two servers and that there are no differences from other servers that never drop. We are running version 12.2 with Postgress