Many VMware virtualization products include vMotion and High Availability, but some IT environments don't need...
these advanced (and costly) features.
If your environment falls into that category, you can use the VMware vSphere Hypervisor, which is the free version of ESXi. This lightweight hypervisor is similar to ESX but lacks the service console. As a result, ESXi's footprint shrinks to approximately 60 MB --a size small enough for virtualization pros even install ESXi on flash drives.
The VMware vSphere Hypervisor lacks some of the features of its full ESXi counterpart, including live migration, load balancing and power management. But small and rudimentary organizations can still benefit from server consolidation without all the bells and whistles of advanced virtualization.
Installing the VMware vSphere Hypervisor
First, download the VMware vSphere Hypervisor from the VMware website. After you log in with a VMware account, which grants access to the software downloads, you'll find it on the VMware's product page. It's a good idea to download the ISO file and burn it to a CD-ROM.
Apart from that, you need to install the VMware vSphere Client on a Windows PC. Also, take note of the license key that appears when you download the software, which you'll need later. ESXi runs as the back-end service on a server, while the vSphere client installs and manages virtual machines (VMs).
Prior to the installation, consider the hardware that will run ESXi. If you want to test-drive it, you don't need a powerful machine. Even a laptop with a minimum of 2 GB of RAM will do, but there are CPU requirements. The CPU must be 64-bit and offer virtualization support in the BIOS. But these requirements usually aren't an issue with recent server hardware.
To create a serious virtual infrastructure, however, it's a good idea to have a minimum of 8 GB of RAM available. (Of course, the grand total depends on what workloads you intend to run.) You should also have a large disk for storing disk image files and at least two network cards to configure in a network interface card bonding configuration.
Creating an ESXi host
To turn a server into an ESXi host, boot it from the installation CD. Choose the ESXi Installer option. After accepting the license agreement with the F11 key, select the hard drive you want to use as the storage device. Typically, it's the local hard disk, but you can use a remote disk if one's available.
You'll probably receive warnings that installing ESXi will wipe everything on the disk. After accepting the message, you can start the installation, and the procedure completes without any interaction. Once you have copied the files to your system, download the management tools from the default IP address that has been assigned by the Dynamic Host Configuration Protocol (DHCP) server in your network. If there isn't a DHCP server or if you want to customize your system, press F2 for customization options.
Before you can configure the system, you need to log in as root. This administrative user account
doesn't have a password by default, so leave the password field blank, and press Enter to log in to the server. You'll see the System Customization interface, where you can create a password. (You don't want the ESXi server accessible to everyone.)
After taking this important step, you should configure the management network to make sure that your ESXi server is always on the same IP address.
Configuring the vSphere Client
The vSphere Client is the basic tool for managing an ESXi server. Through the homepage of a freshly installed server, you can install the vSphere Client on a Windows computer. After starting the vSphere Client for the first time, you need to assign a license to the ESXi host. You can apply for a free license on the VMware website or by following the link that's displayed on the VMware Evaluation Notice after vSphere Client is started. At this point, it's important to enter the license key. If you don't, when the 60-day evaluation period concludes, you can run into major problems.
The option to add a license is hard to find. After selecting the host server from the Inventory page, select Configuration. On that page, click Software and then Licensed Features. An edit link appears on the top right-hand side of the window. After clicking it, select "Assign a new license key to this host" and click the Enter key. Next, type the key that you registered before downloading the software.
After adding the license, you can start working with VMs. An easy way to get familiar with your environment is by download and install a virtual appliance from the VMware Virtual Appliance Marketplace.
About the expert
Sander van Vugt is an independent trainer and consultant based in the Netherlands. Van Vugt is an expert in Linux high availability, virtualization and performance and has completed several projects that implement all three. He is also the writer of various Linux-related books, such as Beginning the Linux Command Line, Beginning Ubuntu Server Administration and Pro Ubuntu Server Administration.