Chris McCain - Mastering VMware® Infrastructure3

A key aspect for the success of virtualization is the ability to allow third-party companies to provide additional products that add value, ease, and functionality to existing products. VMware has shown its interest in allowing third-party software development houses to play an integral part in virtualization by providing an application programming interface (API) to VirtualCenter. This API allows companies to develop custom applications that can take advantage of the virtual infrastructure created in VirtualCenter. For example, Vizioncore's vRanger Pro, a product we will look at in our appendix of tools, is a simplified backup utility that works off the exact inventory created inside VirtualCenter to allow for advanced backup options of virtual machines.

This chapter will cover the installation, configuration, and management of VirtualCenter. In addition, you will find helpful information about best practices for VirtualCenter maintenance, availability, and disaster recovery. A detailed look at templates will be provided in Chapter 6, and Chapter 11 will offer an in-depth look at ESX Server and virtual machine monitoring.

By now, you have a good understanding of the importance of VirtualCenter in a large enterprise environment. As noted in the introduction to this chapter, all things VirtualCenter are stored in a back-end database. So the truth is that the back-end database, not so much the front-end VirtualCenter, is the key component. Without the back-end database, you will find yourself rebuilding an entire infrastructure. Figure 5.4 illustrates the components of a typical Virtual Server infrastructure.

Figure 5.4VirtualCenter acts as a proxy for managing ESX Server 3.0 hosts. All of the data for Virtual-Center is stored in an external database.

Losing the server that runs VirtualCenter might result in a small period of downtime; however, losing the back-end database to VirtualCenter could result in days of downtime and extended periods of rebuilding.

As with most enterprise-level databases that store critical company data, you will want to take especially good care of and take precautions with the VirtualCenter database. Whether this means building the database on a server cluster that provides high availability, or developing a rock-solid backup strategy to ensure smooth and timely restore in the event of loss, measures must be taken to guarantee access and availability of VirtualCenter data.

In light of the sensitive and critical nature of the data in the VirtualCenter database, VMware will only support VirtualCenter issues with back-end databases on enterprise-level database applications. VirtualCenter 2.0.1 supports the following database applications:

♦ Oracle 9 i

♦ Oracle 10 g

♦ Microsoft SQL Server 2000 with Service Pack 4

♦ Microsoft SQL Server 2005 with Service Pack 1

♦ Microsoft SQL Server Desktop Engine (MSDE)

SQL Server 2005 Service Pack 1 is not supported on VirtualCenter 2.0.0. To use SQL Server 2005 Service Pack 1 as the back-end database for VirtualCenter, you must be running VirtualCenter 2.0.1 or higher.

For administrative purposes, you might find it easy to install the database application and the VirtualCenter application on the same computer. This configuration, however, is not considered best practice as you would then have a single point of failure for two core components of the virtual infrastructure. The more common, and recommended, infrastructure design includes deploying VirtualCenter and its back-end database on two different computers. Later in this chapter we will explore some options for building a highly available VirtualCenter installation.

Connecting VirtualCenter to its back-end database requires that an Open Database Connectivity (ODBC) connection be created on VirtualCenter. The ODBC connection should be created under the context of a database user who has full rights and permissions to a database that has been created specifically for storing VirtualCenter data.

Working with Oracle as the back-end database naturally involves more effort than using a SQL Server back-end. I stress the naturally part only because VirtualCenter is a Windows-based application and therefore seems to have a tighter integration with SQL Server that facilitates the configuration. To use Oracle 9i or 10g, you will need to install Oracle and create a database for VirtualCenter to use. If your Oracle database resides on the same computer as VirtualCenter, perform the following steps to prepare Oracle for VirtualCenter:

1. Install the Oracle database driver to the VirtualCenter server.

2. Increase the number of open available cursors for the database by adding the following line:

open_cursors - 300 to the C:\Oracle\Admin\VPX\pfile\init.ora

3. Create a new tablespace dedicated to the VirtualCenter:

CREATE TABLESPACE vc DATAFILE 'C:\Oracle\ORADATA\VPX\vpx.dat' SIZE 250M;

4. Create a new Oracle user account (i.e., vdcdbuser) to use in the ODBC connection string:

CREATE USER vdcdbuser IDENTIFIED BY vdcdbuser DEFAULT TABLESPACE vc;

5. Ensure the database user has been given the CONNECT and DBA privileges.

6. Finally, create an ODBC connection string in the VirtualCenter server using Administrative Tools. Give the ODBC connection a meaningful name and utilize the account created for VirtualCenter access.

For larger enterprise networks where the Oracle 9i or 10g database server is a separate computer, you will need to perform the following tasks on the computer running VirtualCenter:

1. If necessary, download and install the Oracle client on the VirtualCenter server.

2. Download and install the Oracle ODBC driver on the VirtualCenter database.

3. Open the tnsnames.ora file in the C:\Oracle\Oraxx\network\admin directory, where xx is the version number of your ESX server.

4. Add the following text to the tnsnames.ora file:

VPX =

(Description =

(Description

(AddressList=

Address=(Protocol=TCP)(Host=vpxd-Oracle)(Port1521)))

Host =

All of the downloadable files required to make VirtualCenter work with Oracle can be found on Oracle's website at http://www.oracle.com/technology/software/index.html.

In light of the existing widespread deployment of Microsoft SQL Server 2000 and Microsoft SQL Server 2005, it is most common to find SQL Server as the back-end database for VirtualCenter. This is not to say that Oracle does not perform as well or that there is any downside to using Oracle. Microsoft SQL Server just happens to be implemented more commonly than Oracle and therefore is a more common back-end for VirtualCenter.

With the introduction of VirtualCenter 2.5, SQL Server 2005 Express Edition is now the minimum database available as a back-end to VirtualCenter. In fact, SQL Server 2005 Express Edition has replaced the MSDE option for demo or trial installations.

Microsoft SQL Server 2005 Express Edition, like MSDE, has physical limitations that include:

♦ 1 CPU maximum

♦ 1GB of maximum of addressable RAM

♦ 4GB database maximum