Hi Srinivasan,
Please verfiy or check for the root cause by following the below steps and let us know where you are struck to proceed further and please mention the errors if ur getting...
1.Verify that the ESX host is in a powered on state.
2.Verify if the ESX host can be reconnected or if reconnecting the ESX host resolves the issue.
3.Verify if the ESX host is able to respond back to vCenter Server at the correct IP address. If vCenter Server does not receive heartbeats from the ESX host, it goes into a not responding state. To verify if the correct Managed IP Address is set, see Verifying the vCenter Server Managed IP Address (1008030)
A. To check if a managed IP has been set on vCenter Server 4.x and above:
From the vSphere Client, log in to vCenter Server
Navigate to Administration > vCenter Server Settings > Runtime Settings and review the Managed IP Address setting.
Verify that the address is correct. If not, correct the entry and click OK to save your changes and close the dialog.
Remove the ESX/ESXi host from the vCenter Inventory.
Add the ESX/ESXi host back to vCenter Inventory.
4.Verify that network connectivity exists from vCenter Server to the ESX host. For more information, see Testing network connectivity with the Ping command (1003486) .
5.Verify that you can connect from vCenter Server to the ESX host on TCP/UDP port 902. If the ESX was upgraded from version 2.x and you cannot connect on port 902, then verify if you can connect on port 905. For more information, see Testing port connectivity with Telnet (1003487) .
C:\>telnet server 25
Connecting...
220 server ESMTP Sendmail 8.13.3/8.13.3;
Connecting to port 443 on the vCenter Server:
C:\>telnet server 443
Connecting...
6.Verify that the ESX management service vmware-hostd is running. For more information, see Verifying that the Management Service is running on an ESX host (1003494) and Troubleshooting vmware-hostd service if it fails or stops responding (1002849).
Run this command:
ps -ef | grep hostd | grep -v grep
The output appears similar to below if vmware-hostd is running:
[root@server]# ps -ef | grep hostd | grep -v grep
root 23204 1 0 15:27 ? 00:00:00 /bin/sh /usr/bin/vmware-watchdog -s hostd -u 60 -q 5 -c /usr/sbin/hostd-support /usr/sbin/vmware-hostd -u
root 23209 23204 1 15:27 ? 00:04:23 /usr/lib/vmware/hostd/vmware-hostd /etc/vmware/hostd/config.xml -u
[root@server]#
The output appears similar to the below if vmware-hostd is not running:
[root@server]# ps -ef | grep hostd | grep -v grep
[root@server]#
7. Verify that the VirtualCenter agent service vmware-vpxa is running. For more information, see Verifying that the vCenter Server Agent Service is running on an ESX host (1003495) .
Type ps -ef | grep vpxa ( if no output means service not running )
8. Verify that the xinetd service is running. If xinetd is not running, authentication may fail. For more information, see Determining if the xinetd service is running on an ESX host (1007323) .
#service xinetd status #service xinetd start
9. Verify if restarting the ESX Management Agents resolves the issue. For more information, see Restarting the Management agents on an ESX or ESXi Server (1003490) .
#service mgmt-vmware restart and #service vmware-vpxa restart
10. Verify that no processes are over utilizing the resources on the Service Console. For more information, see Checking for resource starvation of the ESX Service Console(1003496) .
Type top. and To exit top, press Q
11. ESX hosts can disconnect from vCenter Server due to underlying storage issues. To investigate further, see Identifying Fibre Channel, iSCSI, and NFS storage issues on ESX/ESXi hosts (1003659)
