Add Remote Datastore Source using vSphere Client fails with "Cannot connect to remote VMware vCenter instance"

Products

• VMware vCenter Server

Issue/Introduction

• Attempting to configure vSAN HCI Mesh to mount a remote datastore, the task may fail during the Check Compatibility stage
  
  

  Check Compatibility

  Remote VMware vCenter instance <remote-vcenter FQDN/IP> has valid network identity.
Remote VMware vCenter instance <remote-vcenter FQDN/IP> can be connected.
The client VMware vCenter instance <client-vcenter FQDN/IP> and server VMware vCenter instance <remote-vcenter FQDN/IP> are compatible for HCI Mesh operations.
Can perform precheck to Remote VMware vCenter instance <remote-vcenter FQDN/IP>.
Cannot connect to remote VMware vCenter instance: <remote-vcenter FQDN/IP>.

  
  
  
• /var/log/vmware/vsan-health/vmware-vsan-health-service.log (on client-vcenter server)

YYYY-MM-DDTHH:MM:SS INFO vsan-mgmt[PID] [DSMgmt::PrecheckDatastoreSource opID=agw-#] Prechecking datastore source <remote-vcenter FQDN/IP> for checkCreateDs
YYYY-MM-DDTHH:MM:SS ERROR vsan-mgmt[PID] [utils::IsLocalVC opID=agw-#] Got exception trying to getaddrinfo from host <remote-vcenter FQDN/IP>
Traceback (most recent call last):
  File "bora/vsan/xvc/lib/utils.py", line 61, in IsLocalVC
socket.herror: [Errno 1] Unknown host
YYYY-MM-DDTHH:MM:SS ERROR vsan-mgmt[PID] [DSMgmt::CheckValidateDs opID=agw-#] Failed to validate Datastore Source
Traceback (most recent call last):
  File "bora/vsan/xvc/DSMgmt.py", line 478, in CheckValidateDs
  File "bora/vsan/xvc/lib/utils.py", line 69, in IsLocalVC
  File "bora/vsan/xvc/lib/utils.py", line 61, in IsLocalVC
socket.herror: [Errno 1] Unknown host

Cause

The issue is caused by a failure in DNS name resolution between the vCenter Server instances. The vSAN management service utilizes the getaddrinfo function to verify the remote vCenter's network identity; if the FQDN cannot be resolved to an IP address, the compatibility pre-check fails.

Resolution

To resolve this issue, ensure that both vCenter Servers can resolve each other's FQDN

If updating the DNS server is not immediately feasible, implement a local host entry workaround:

1. Access the shell of both the Client vCenter
2. Open the /etc/hosts file using a text editor (e.g., vi /etc/hosts)
3. Add entries for both vCenter Servers using their respective management IP addresses and FQDNs
   
   #.#.#.#  remote-vcenter.example.com
#.#.#.#  client-vcenter.example.com
   
   
4. Save and close the file.
5. Retry the Add Remote Datastore Source task in the vSphere Client.