Cannot Connect to ESXi Server (code 1909)

Situation

A VMware backup plan terminates with the following error: Cannot connect to ESXi server. Connection refused

Cause

Typically, this error occurse on ESXi server side, so actions should be taken there as well.

Solution

Basic solutions for this issue are:

  • ESXi host rebooting
  • Disconnecting ESXi host оn vCenter and try to reconnect using IP address instead of FQDN

Reboot ESXi

Warning: Although these methods will gracefully shut down or reboot an ESXi/ESX host, they will not safely stop running virtual machines on the host. You should always ensure that virtual machines are migrated off the host and that the host is in maintenance mode before attempting to reboot or shut down a host using any method.

For ESX 4.x

Once you are logged in the ESX console, run the following command: reboot to reboot the system.

You can shut down the host as well, using the poweroff. Once you shut the host down, you can reboot it by starting it up again

For ESXi 4.x/5.x/6.x

In the Direct Console User Interface, press F11. This command reboots the ESXi host.

Disconnect an ESXi Host on vCenter

Proceed as follows:

  1. Right-click Host in the VMware Host Client inventory, the select Disconnect from vCenter Server.
  2. Run Add Host wizard.
  3. In the Connection Settings, type the new ESXi host IP address and the root credentials for the host, then click Next.
  4. In the Security Alert dialog box, click Yes.
  5. Click Yes in the Duplicate Management warning message for the HA cluster.
  6. On the Host Summary and Virtual Machine pages, click Next.
  7. On the Ready to Complete step, click Finish.