Error cannot synchronize host cannot contact the specified host в ESXI 5.5
Cause
The issue occurs when the vpxuser password is out of sync with the vCenter Server database and the password on the host or the password has been manually modified.
The vpxuser account is created by vCenter Server when adding an ESX host. It is not recommended to modify the vpxuser account.
Resolution
To resolve this issue, resync the password with the vCenter Server database. The host will reconnect without the error on the Summary tab.
Caution: Do not remove the host from the inventory. When an ESX/ESXi host is removed from vCenter Server inventory, virtual machines are removed from their respective folders, performance data for the host is lost, and any Distributed Virtual Switch configurations on the host needs to be reconfigured.
To resync the password with the vCenter Server database:
- Disconnect the host from vCenter Server.
- Reconnect the host and enter in the root password when prompted.
Материал сайта pyatilistnik.org
Спасибо, очень помогла статья.