Symptoms
- ESXi/ESX host shows as Not Responding in vCenter Server/VirtualCenter
- ESXi/ESX host shows as Disconnected in vCenter Server
- Cannot connect ESXi/ESX to vCenter Server
- Virtual machines on the ESXi/ESX host shows as grayed out in vCenter Server.
- When attempting to add an ESXi/ESX host to vCenter Server, you see an error similar to:
Unable to access the specified host, either it doesn't exist, the server software is not responding, or there is a network problem
Purpose
This article guides you through the process of troubleshooting an ESXi/ESX host that is in a disconnected or a not responding state in vCenter Server. It provides steps to help you eliminate common causes for your problem by verifying that the configuration of your networking and management server agents is correct, as well as confirming the availability of resources on your ESXi/ESX host.
Resolution
Validate that each troubleshooting step below is true for your environment. Each step will provide instructions or a link to a document, in order to eliminate possible causes and take corrective action as necessary. The steps are ordered in the most appropriate sequence to isolate the issue and identify the proper resolution. After each step, try to connect to vCenter Server. Do not skip a step.
For ESXi
- Verify that the ESXi host is in a powered on state.
- Verify if the ESXi host can be reconnected or if reconnecting the ESXi host resolves the issue. For more information, see Changing an ESXi or ESX host's connection status in vCenter Server (1003480) .
- Verify if the ESXi host is able to respond back to vCenter Server at the correct IP address. If vCenter Server does not receive heartbeats from the ESXi 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).
- Verify that network connectivity exists from vCenter Server to the ESXi host. For more information, see Testing network connectivity with the Ping command (1003486) .
- Verify that you can connect from vCenter Server to the ESXi host on TCP/UDP port 902. If the host 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).
- Verify if restarting the ESXi Management Agents resolves the issue. For more information, see Restarting the Management agents on an ESX or ESXi Server (1003490).
- ESXi hosts can disconnect from vCenter Server due to underlying storage issues. To investigate further, seeIdentifying Fibre Channel, iSCSI, and NFS storage issues on ESX/ESXi hosts (1003659).
For ESX
- Verify that the ESX host is in a powered on state..
- Verify if the ESX host can be reconnected or if reconnecting the ESX host resolves the issue. For more information, see Changing an ESXi or ESX host's connection status in vCenter Server (1003480) .
- 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) .
- Verify that network connectivity exists from vCenter Server to the ESX host. For more information, see Testing network connectivity with the Ping command (1003486) .
- 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) .
- 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) .
- 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) .
- Verify that the xinetd service is running. If xinetd is not running, authentication may fail. For more information, seeDetermining if the xinetd service is running on an ESX host (1007323) .
- 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) .
- Verify that no processes are over utilizing the resources on the Service Console. For more information, seeChecking for resource starvation of the ESX Service Console(1003496) .
- ESX hosts can disconnect from vCenter Server due to underlying storage issues. To investigate further, seeIdentifying Fibre Channel, iSCSI, and NFS storage issues on ESX/ESXi hosts (1003659)
Note: If your problem still exists after trying the steps in this article:
- Gather VMware Support Script Data. For more information, see Collecting Diagnostic Information in a VMware Virtual Infrastructure Environment(1003689) .
- File a support request with VMware Support and note this KB Article ID in the problem description. For more information, see How to Submit a Support Request .Based on VMware KB 1003409
