With ESX 4.1, you can use Web Access to manage your VMware ESX server,
especially, if you have Linux or OS X. In some cases, you may receive 503
Service Unavailable when using ESX Web Access.
Resolution: 1. You may need to start the Web Access Service in the ESX
server. to do that, please follow these steps:
1) Login root to your vmware server.
2) Type the following command to turn on the service:
# chkconfig vmware-webAccess on
# service vmware-webAccess start
Note: vmware-webaccess is case sense.
2. Make sure you have enabled vSphere Web Access in
Firewall. To do that, please follow these steps:
1) Logon vSphere client.
2) Highlight the ESX host and select Configuration tab.
3) Click Security Profile under Software.
4) Check the vSphere Web Access. and click OK
to save the settigns.