Implementing VMware vCenter Server: This book starts with the basics then leads you by the hand through a complete Vmware vCenter Server implementation course. Designed to help you administer and manage your environment on a day to day basis.

vCenter performs the following three main functions:

The main features of vCenter are:

There is a lot of confusion out there regarding VMware terminology. Part of the issue is that VMware has been changing terminology with every new version. In this section, we'll describe a few important terms that are widely used and which will also be used in this book.

VMware vSphere is VMware's server virtualization suite. This software bundle was called VMware Infrastructure 3 (VI3). When VMware Infrastructure 3.5 (VI3.5) was in development, vSphere was considered as an advanced suite of tools utilizing VMware ESX/ESXi4. At the same time, VMware was developing VMware Infrastructure 4 and eventually vSphere 4 was announced and released in May 2009 instead of VI4.

In November 2009, Update 1 for vSphere 4 was released with support for Windows 7 and Windows Server 2008 R2.

vSphere 4.1 became available in August 2010. This version included an updated vCenter Configuration Manager and vCenter Application Discovery Manager as well as vMotion capability.

Update 1 for vSphere 4.1 was released in February 2011 with added support for Red Hat Enterprise Linux (RHEL) 6, RHEL 5.6, SLES 11 SP1, Ubuntu 10.10, and Solaris 10 Update 9.

On July 12, 2011, VMware released Version 5 of VMware vSphere.

On August 27, 2012, VMware released its latest version of the suite; that is, VMware vSphere 5.1. This update extends vSphere to also include VMware vSphere Storage Appliance, vSphere Data Protection, vSphere Replication, and vShield Endpoint.

Depending on the version and license, vSphere includes, but is not limited to, the following features:

More information on most of these features is available in the following chapters. In the following section, we will give their brief overview.

ESX/ESXi is a bare metal-embedded hypervisor. It runs on the virtualization layer that abstracts physical server resources, such as CPU, memory, and storage, into multiple virtual machines.

Hypervisor is a software or hardware that creates and runs virtual machines. The computer it's running on is called the host. Virtual machines are often referred to as guests. A hypervisor allows guest operating systems to run with an appearance of full access to underlying systems. During this process, the system's resources that are shared among multiple virtual machines and are accessed by VMs are under the complete control of the hypervisor.

There are two types of hypervisors:

An embedded hypervisor is a type 1 hypervisor that supports the requirements of embedded systems development. Embedded systems, in contrast with general purpose computers that are supposed to meet a wide range of requirements, are designed for specific control functions within larger systems. Often, real-time constraints have to be addressed as well.

The hypervisor requirements suitable for embedded applications are quite different from the hypervisor requirements aimed at enterprise applications. These requirements are briefly summarized as follows:

The description of the previously mentioned features of vSphere is as follows:

The most important features previously mentioned are summarized in the following diagram:

The VMware software stack consists of three layers: virtualization, management, and interface. The relationship between these layers is shown in the following figure:

The virtualization layer of VMware vSphere consists of infrastructure services and application services. Infrastructure services abstract, aggregate, and allocate all hardware and other resources. Infrastructure services include:

Application services are designed to ensure availability, security, and scalability for applications; for example, features such as vSphere High Availability and Fault Tolerance.

The management layer is represented by VMware vCenter Server, which is the main central point for configuring, provisioning, and managing your virtual environment.

The interface layer is where user access to vSphere happens. Users can access the environment using GUI clients such as vSphere Client or vSphere Web Client. Also, users can access the datacenter using command-line interfaces or SDKs for automated management or third-party product connections.

vCenter Server comes in two editions: Standard and Foundation. Foundation is designed for small- and middle-sized environments and can manage up to three hosts. The Standard edition is for large vSphere deployments.

VMware vCenter Server Foundation edition includes the following capabilities:

VMware vCenter Server Standard Edition includes all the capabilities of vCenter Server Foundation plus the following capabilities:

vCenter Server has to be purchased separately on a per-instance basis.

vCenter Server can also be purchased as part of VMware vSphere Essentials Kit. It supports up to three hosts with up to two processors per host, includes one license for vCenter Server Essentials, and is a great starter kit for small businesses.

VMware vSphere Essentials Bundle includes the following:

VMware vSphere Essentials Plus Kit includes all the benefits of Essentials and the following additional benefits:

There is an option to purchase the support plan along with the software. The basic support plan is meant for non-critical environments that require support only during business hours. The production plan offers global 24 x 7 support for production environments where a fast response time is required for critical issues.

Both plans include an unlimited number of support requests and remote support as well as product updates and upgrades.

It is important to remember that vCenter Server is an additional product that is licensed separately from vSphere on a per-instance basis, while vSphere is licensed per processor. vSphere 4.1 has additional restrictions for the number of cores per CPU as well as memory capacity per host (see the following list); vSphere 5 licensing removes all these restrictions.

vSphere 4.1 additional licensing restrictions are as follows:

A review of vSphere editions is out of the scope of this book. More information can be found on the VMware website and in the VMware vSphere Licensing, Pricing and Packaging white paper in particular.

The VMware license key is a 25-character alphanumeric string that contains encrypted information about the software edition purchased and restrictions such as processor quantity for vSphere. It doesn't contain any server or hardware-specific information. This means that the same license key can be assigned to multiple vSphere hosts as long as the quantity of physical processor on these hosts doesn't exceed the quantity included with the license.

vCenter Server is the recommended interface for managing vSphere licenses. When a license key is installed in vCenter, it's copied to the host and kept there in the persistent format. The license key remains active after the host is rebooted or disconnected from vCenter Server. If a key needs to be removed or replaced, it has to be done manually by the administrator.

According to VMware documentation, vCenter Server setup is an optional step for vSphere deployment. As you will see later in this book, however, vCenter offers a huge amount of features and options for managing the vSphere environment. It also simplifies management and adds flexibility. It's useful for any administrator and/or environment no matter how large or small. It's fair to say that vCenter is an essential component of every professional vSphere deployment and for each more or less critical environment.

vCenter 5.0 deployment consists of the following tasks:

vCenter 5.1 deployment consists of the following tasks:

More information on each of these steps will follow.

vSphere physical topology

A common VMware vSphere datacenter physical topology is shown in the following figure. It may be useful for better understanding of the different vSphere components and the relationships between them.

There are three interfaces that can be used to manage the vSphere environment and access virtual machines: VMware vSphere Client (vSphere Client), vSphere Web Client for access through a web browser, and vSphere Command-Line Interface (vSphere CLI). They are shown on top of the preceding figure.

Computing servers are shown at the center of the preceding figure. Each computing server is an ESX or ESXi host with one or multiple virtual machines running on it. When there are two or more hosts, they can be grouped into clusters to provide an aggregate set of resources and to take advantage of features such as fault tolerance, high availability, and so on.

Storage networks and arrays are shown at the bottom of the preceding figure. Depending on the environment, there may be Fibre Channel SAN arrays, iSCSI SAN arrays, NAS arrays, or their combinations. Storage arrays are usually connected to computing servers, and in most cases, they are connected through a separate network—Storage Area Network (SAN). This is often referred to as a third network after the management network, and it's also called the network or networks virtual machines are part of.

vCenter Server is shown as a separate physical server. Depending on how your infrastructure was designed, it can also be a virtual server located in one of the server groups. When vCenter is separate, computing servers continue to function in case vCenter Server becomes unreachable and the other way round. If one or few of the computing servers go down, you are still able to manage the rest of the environment using vCenter Server.

Once all hardware and software prerequisites are met, before running the installer, make sure that:

vCenter Server and vSphere Update Manager require the database server to store its data, and each vCenter Server instance requires its own database. Also, it is recommended to use separate databases for vCenter Server and Update Manager.

vCenter can use DB2, Oracle, or MS SQL database. Microsoft SQL Server 2008 R2 Express can be used for smaller deployments—up to five hosts and up to 50 virtual machines. It will be installed during vCenter setup if you select the bundled database during installation. It's not supported for production environments however. Microsoft SQL Server 2005 or 2008 can be used for larger deployments.

For any supported databases, vCenter needs a 64-bit System DSN. If you are using the Microsoft SQL Server database on a different server, System DNS can be created by navigating to Control Panel | Administrative Tools | Data Sources (ODBC). In the ODBC settings window, go to the System DSN tab. From there, you can either modify the existing ODBC connection or create a new one. To create a new connection, click on Add, select SQL Native client, and then click on Finish.

In the next step, enter the ODBC data source name, an optional description, and the SQL Server name. You may need to type the name in the dropbox if it's not listed there.

In the next step, choose either Integrated Windows Authentication or SQL Server authentication and enter the username and password if necessary. Select the database that will be used and then click on Finish. There is also an option to test the connection.

If you don't have a database ready yet, please refer to the section about setting up a database later in this chapter.

If the server name has been changed, make sure System DSN is configured to use the new name.

Once the vCenter Server database is in use, it's a good idea to perform standard database maintenance regularly. The suggested maintenance tasks are:

Keep in mind that when you install vCenter Server, there are other components that will be installed as well. A list of the components that are installed by default can be found in the VMware documentation at http://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.install.doc%2FGUID-78933728-7F02-43AF-ABD8-0BDCE10418A6.html.

The vCenter Server that is installed is usually downloaded as a ZIP archive. Once it's downloaded and unzipped, run autorun.exe and select vCenter Server.

The next steps of the installation wizard are straightforward. You will be prompted to choose the installer language, accept the end user and license agreement, and enter your username, organization name, and license key.

The license key can be omitted in this step. In this case, vCenter Server will be in the evaluation mode that allows you to use the full feature set for a 60-day evaluation period. You will be able to enter the license key later and convert vCenter Server to the licensed mode.

In the next step, choose the type of database that you want to use:

In the next step, you'll need to set the login information for vCenter Server:

In the next step, the Fully Qualified Domain Name field of the system that you are installing vCenter Server on is displayed. The installer checks that this FQDN is resolvable. A warning message will be displayed if FQDN is not resolvable. This is a requirement, so you may need to change the entry to a resolvable one. FQDN has to be entered in this step, not an IP address.

In the next step, you can either accept the default destination folders or click on Change to select another location.

Moving forward, select Create a standalone VMware vCenter Server instance or Join Group. When joining a Linked Mode group, you can enable vSphere Client to view, search, and manage data across multiple vCenter Server systems.

If you join a group, enter the fully qualified domain name and LDAP port number of any remote vCenter Server system. The installer will allow entering IP address as well. However, to make sure that you don't run into any issues in future if the IP address changes, it is recommended to use FQDN.

For IPv6, it's better to use FQDN especially when a local or remote server is not in the IPv6 mode. If the local machine has an IPv4 address and the remote machine has an IPv6 address, make sure the local machine supports IPv4 and IPv6 mixed mode. The domain name server should also be able to resolve both IPv4 and IPv6 addresses if there are servers that use different addressing types in a single Linked Mode group.

In the next step, enter the port numbers that you want to use or accept the default port numbers.

Then, select the size of your vCenter Server inventory, which helps the installer to allocate memory for several Java services that are used by vCenter Server.

Optionally, choose Select this option to increase the number of ephemeral ports available option in the Ready to Install the Program window. This option increases the number of available ephemeral ports. In case more than 2000 virtual machines are powered on simultaneously on different hosts managed by vCenter, this option prevents the pool of available ephemeral ports from being exhausted.

Click on Install; once installation is done, click on Finish.

After vCenter Server is installed, you may need to install additional modules. Some of them are listed as follows:

All the previous modules can be installed by selecting the appropriate option from the Autorun menu of the vCenter Server installer.

If there is a requirement for strong security, it's recommended to replace default vCenter Server certificates with certificates signed by a trusted Certificate Authority (CA). If you don't have a certificate yet, you will need to create a certificate signing request (CSR), submit it to CA, and get a certificate. This can be done with OpenSSL on any Windows or Linux machine. In most cases, OpenSSL needs to be installed on the server.

Once you receive the certificate, you will need to export it as a .pfx file, which combines the certificate and private key. This can be accomplished using the following command:

openssl pkcs12 -export -in <name>.crt -inkey <name>.key -name <name> -passout pass:testpassword -out <name>.pfx

The .crt file contains the certificate and the .key file contains the private key.

If you have a certificate that you can use with vCenter, it's likely a .pfx file already, and you will need to split it into the certificate and private key as shown in the following lines of code :

openssl.exe pkcs12 -in <name>.pfx -nocerts -out <name>.pem
openssl.exe pkcs12 -in <name>.pfx -clcerts -nokeys -out <name>.pem

Eventually, you will have three files: .crt, .key, and .pfx. For vCenter Server 5.0 and later, you must also copy the certificate files to the vSphere Web Client directory and to the Inventory Service directory. Therefore, these files will need to be placed in the following folders:

In case you choose not to use the bundled database option for vCenter Server deployment, there are certain requirements and steps that need to be done to set up a database.

Using Microsoft SQL Server is the most common practice, and further on in this section, we will be assuming this database is used. More information on other supported databases—IBM DB2 and Oracle—can be found in the VMware vCenter Server documentation.

Microsoft SQL Server 2008 R2 Express can be used only as a bundled option for deployments with up to five hosts and 50 virtual machines. If you choose to use Microsoft SQL Server 2005 or Microsoft SQL Server 2008, make sure the machine has a valid ODBC DSN entry.

The first step is to create a database and user. This can be accomplished from Microsoft SQL Server Management Studio using the following script from /<installation directory>/vpx/dbschema/DB_and_schema_creation_scripts_MSSQL.txt:

use [master] 
go 
CREATE DATABASE [VCDB] ON PRIMARY 
(NAME = N'vcdb', FILENAME = N'C:\VCDB.mdf', SIZE = 2000KB, FILEGROWTH = 10% ) 
LOG ON 
(NAME = N'vcdb_log', FILENAME = N'C:\VCDB.ldf', SIZE = 1000KB, FILEGROWTH = 10%) 
COLLATE SQL_Latin1_General_CP1_CI_AS 
go
use VCDB 
go 
sp_addlogin @loginame=[vpxuser], @passwd=N'vpxuser!0', @defdb='VCDB', @deflanguage='us_english'
go 
ALTER LOGIN [vpxuser] WITH CHECK_POLICY = OFF 
go 
CREATE USER [vpxuser] for LOGIN [vpxuser]
go
use MSDB
go
CREATE USER [vpxuser] for LOGIN [vpxuser]
go

Once the database and user have been created, the user needs to be assigned the db_owner role for the database.

The next step is to configure the ODBC connection. As described earlier, this can be done by navigating to Control Panel | Administrative Tools | Data Sources (ODBC).

For vCenter statistics to function properly, the remote SQL server needs TCP/IP to be enabled for the database. To accomplish this, perform the following steps:

Once vCenter Server is installed, you can go to http://<Your vCenter server IP address or FQDN name> and click on Download vSphere Client. vSphere Client installation is straightforward. Make sure the user you are working under has local administrator rights on the machine and the system has an Internet connection.

Run vSphere Client by navigating to Start | Programs | VMware | VMware vSphere Client and type vCenter Server's or the host's address; if you are connecting directly to a host, enter the username and password.

You can ignore the security warning that appears. If you are not able to connect, make sure that the VMware VirtualCenter Management Webservices service on the server is running.

vSphere 5 also offers vSphere Web Client, which is an application that provides a browser-based alternative to the traditional vSphere Client. With vSphere Web Client, administrators can use a web browser to connect to vSphere or directly to the ESXi host through a vCenter Server.

In Version 5.1 and later of vSphere, web client becomes a core administrative interface for your virtual environment and comes with additional features not available in vSphere Client, which are listed as follows:

To install and start vSphere Web Client, you will need the vCenter installer. Launch autorun.exe, select the VMware vSphere® Web Client (Server) option, and then click on Install. Follow the wizard to finish installation. Once it's completed, register one or more vCenter servers on the vSphere Web Client Administration application page in the browser. You will need to use the address in IPv6 format if your vCenter uses an IPv6 address or enter FQDN, which is preferable.

vSphere Client hardware requirements are:

vSphere Client requires Microsoft .NET Framework 3.5 SP1. If it is not installed, it will be deployed by the vSphere Client installer.

The operating systems supported by vSphere Client are Windows clients starting from Windows XP Service Pack 2 and Windows servers starting from Windows Server 2003 Service Pack 2.

The vSphere Web Client hardware requirements are:

The following browsers are supported by vSphere Web Client 5:

vSphere Web Client 5.1 also supports:

The operating systems supported by vSphere Web Client are:

vSphere Web Client also requires Adobe Flash Player Version 10.1.0 or later to be installed with the appropriate plugin for your browser.

vCenter is a tool for the centralized management of the vSphere suite. It allows the management of multiple ESX/ESXi servers and VMs through a single-console application.

The VMware software stack consists of three layers: virtualization, management, and interface layers.

vCenter Server comes in two editions: Standard and Foundation. Foundation is designed for small- and middle-sized environments and is able to manage up to three hosts. Standard edition is for large vSphere deployments.

vCenter deployment consists of the following tasks:

Before starting vCenter deployment, you need to make sure that all prerequisites and requirements are met.

There are two approaches to the deployment of vCenter Server: it can be deployed on a virtual server or on a physical server.

Virtual machines are easier to manage; so, in other words, you get all the advantages related to virtualization while deploying vCenter on a virtual server.

On the other hand, running virtualized vCenter has certain concerns.

A Linked Mode group is a group of vCenter servers. It allows administrators to connect to one of them and manage inventories from all vCenter Servers in the group.