This happens most often when VitualCenter Server 2.0 is used to VMotion between ESX 2.5.3 Server hosts.
Test the following before starting VMotion.
- Ping the hostname of the target ESX Server host from the source ESX Server host.
- Ping the hostname of the source ESX Server host from the target ESX Server host.
- Ping the hostnames of both ESX Server hosts from the VirtualCenter Server host.
If ping fails for any of these tests, check your DNS settings. Page numbers 48-49 of the Server Configuration Guide explains how to set up DNS and Routing using VI client. https://www.vmware.com/pdf/vi3_server_config.pdf
If you do not use a DNS server for ESX Server hosts, edit the /etc/hosts file on each ESX Server host so that it contains the IP and hostname of other ESX Server hosts.
A sample /etc/hosts file is shown below.
127.0.0.1 localhost.localdomain localhost
10.16.23.89 target-esx.domain.tld target-esx
10.16.23.88 source-esx.domain.tld source-esx
Also, on the VirtualCenter Server machine, put the IP and hostnames of all ESX Servers hosts that are managed by VirtualCenter in the ’windows’system32’drivers’etc’hosts file.
After configuring the name resolution, restart VirtualCenter 2.x services and try VMotion.