If you are still using full ESX servers in your VMware environment, and you want to use Veeam Backup, keep in mind this problem and its solution.
When you add an ESX node to Veeam Backup, you are asked for credentials to login to the node, these can be the root account (if you edit sshd_config to allow root login) or another user you created.
By default, Veeam connects to the ESX server using automatic mode of the Data Transfer Engine. This mode creates several problems, and you will end up most of the times with this error:
This it the solution:
– right clic on the ESX server listed in Veeam Backup and choose Properties
– open the tab “Data Transfer”
– “Data transfer engine” is configured by default with Automatic Selection. Change to “Force Agentless mode”
In this way your backups will continue without errors.