I was on the phone with Dell VMWare support last night for just this question. The following restarts all the management services and worked for us. We don't use OME, but OMSA on the VMWare host no longer accepted remote management logins.  The following fixes it without a host reboot. /sbin/services.sh restart
 Hi,   Recently I installed a Dell OpenManage Essentials server to monitor my ESX 5.0U1 hosts. I installed the 7.1 VIB via update manager and all was well. I could detect and inventory the hosts in OME and in the troubleshooting tool I could connect via WSMAN and retrieve all server details. I also had the servers succesfully send snmp traps to the OME server. I hadn't look at any of this for a few weeks but noticed this morning that the OME server could no longer see any of the ESX servers and WSMAN would not connect.  I want to restart the dell agents/services on the ESX hosts without rebooting but dont know the CLI commands. Could someone help please.   Thx
Restart Dell OMSA ESX agents manually