vCenter bug with Oracle 11g databases

Problem:
There is a known bug with vCenter not closing database connections on Oracle DB's properly when shutdown. As a result when your vCenter server tries to start its services you may receive an error saying "Unable to get exclusive access to VC repository.Please check if another VirtualCenter instance is                           running against the same database schema."

Resolution:
The fastest resolution to this problem is to kill the open connections on the Oracle Database and then start the services normally. 

In addition to that VMWare has a long term solution to stop this from happening until a patch is released. The KB below has the details of the fix. 
http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1021194

Troubleshooting vCenter 5.1 Single Sign On Installation Problems

During the installation of vmware vCenter 5.1 Single Sign On i couldn't get past the step requesting the database information. I was installing SSO in a development environment using sql server 2008 express with the default instance name of vim_sqlexp. During the install i kept getting errors saying it couldn't find the instance of sql server. Below are the steps i used to resolve this issue.

1. Open SQL Server Configuration Manager and make sure the TCP/IP protocol is enabled and make sure that the port is listed as 1433.
2. On the SSO Database Information Screen do not specify the instance name. Even if you are using a database instance only type the server name, make sure the port and database is correct and click next.
3. The install script should automatically find the instance that contains the RSA database that is required by the Single Sign On Service.

Suppressing SSH warning on ESXi hosts

By default ESXi 5 hosts will display a notification when you turn on the SSH service. It is good practive to limit the amount of service that are open on your server, however i think there are a lot of very compelling reason to enable this SSH. The steps below will show you how to suppress the warning notification on ESXi hosts.

If you want to disable the warning and the exclamation mark do the following:

1. Select the ESXi host in the Inventory tab.
2. Click the Configuration tab.
3. Under Software, click Advanced Settings.
4. Click UserVars.
5. Change the value of UserVars.SuppressShellWarning to 1.
6. Click OK.