VMware vSphere PowerCLI Reference. Graf Brian

ISO

      • The Installation Medium

      • Gathering Required Software

      • Automate an Installation

      • Customizing an Installation with Kickstart

      • Postinstallation Configuration

      There was a time when automating an installation and configuration of the vSphere Hypervisor was quite difficult. Fortunately, VMware has worked hard to simplify the overall process. Today 90 percent of the installation is automated out of the box. In this chapter we will briefly walk through the various installation methods before taking a deep dive into automating that last 10 percent. We will cover several techniques for streamlining the installation and configuration of vSphere.

      Prepare for an Installation

      The first step in preparing for an installation is to ensure that your install media is up-to-date and has all of the needed drivers and other vendor packages for your servers. This includes things like storage vendor plug-ins, as well as the Fiber Channel Host Based Adapter (HBA), NIC, SCSI controller, and IPMI/CIM drivers that enable vSphere to better interact with your hardware and provide increased performance, stability, and reporting. PowerCLI has a feature known as the Image Builder CLI, which enables you to manage the packages contained in the install ISO and customize them for your needs.

      Customizing the vSphere ISO

      VMware ships the ESXi ISO with many default packages. You may not need all of them. Often, you need additional drivers. The install image can be customized using PowerCLI. You can tailor it specifically for your environment and include only those packages that are required for your servers.

      To get started, make sure that you have downloaded the offline bundle for the version of ESXi you plan to use. Offline bundles are zip files that typically are much larger than the default ISO download. Once you have downloaded an offline bundle, download to the same directory the driver packages that you need. Like the ESXi packages, if your vendor gives you options for online or offline bundles, choose the offline bundle.

To start, you need to add the packages that have been downloaded, which are treated as depots of software packages by PowerCLI. Listing 2-1 shows how to make the Image Builder CLI aware of a downloaded update package. We also want to make sure that the PSSnapin that provides the cmdlets has been added to the environment.

Listing 2-1: Adding an offline bundle package as a software depot

      TIP VMware provides a public Internet–accessible repository of all images and update packages at this address:

      https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml

      Using this address as the location for the repository ensures that you always have access to the most recent versions of drivers and ESXi. Remember that you must have Internet connectivity, and be sure to take into account how long it will take to download the packages.

You can add as many of these bundles as needed to the cmdlet in Listing 2-2, which checks for packages that have been added and shows an example return.

Listing 2-2: Showing available bundles

Each bundle contains one or more software packages that will be combined, using the cmdlets, to make the customized install media for your installation. To list the available packages, use the Get-EsxSoftwarePackage cmdlet. The most interesting will be the non-VMware packages, since these are the ones you are probably trying to add to the default set. In Listing 2-3, we use PowerShell to show only those packages that are not part of VMware’s default bundle.

Listing 2-3: Listing non-VMware software packages

After you have downloaded the bundles, you can begin to modify the default images to customize them for your environment. Each bundle includes several image profiles; you can build an image profile to meet your needs from there. To view the existing image profiles, use the Get-ESXImageProfile cmdlet, as we did in Listing 2-4.

Listing 2-4: Showing available image profiles

      The packages have three basic types: Standard, which includes VMware Tools; No-tools, which is self-explanatory; and those that have a name ending with “s,” which are security updates images. The steps for creating a package are as follows:

      1. Clone the base profile.

      2. Add and remove packages as needed.

      3. Export the profile.

Listing 2-5 shows the PowerCLI used to execute those steps and ends by exporting the modified profile as an ISO image that can be used for loading your servers.

Listing 2-5: Modifying the ESXi profile

Pipelining the commands makes for an easy way to do all three operations (clone, add, and remove) in one simple step. The final operation is to export the newly customized installation profile to an ISO image (see Listing 2-6).

Listing 2-6: Exporting the customized image

      The final parameter for the command can be either ExportToIso, which will output an ISO that can be used to install vSphere to the host, or ExportToBundle, which will output a bundle capable of being ingested by Update Manager or directly on the host for providing updates to packages.

      Now that you have ensured the drivers and other packages for your physical servers are a part of the default install package, let’s investigate the different ways of loading the OS onto the physical host.

      The Installation Medium

      There are several different methods to install vSphere, ranging from the humble CD/DVD to the more complex, but more flexible, PXE. The installation method is the starting point from which you work backward. Once you have selected an install medium, you then tailor your automation and workflows to that method.

      A large part of choosing the installation method is related to the size of your vSphere environment. Each of the available methods carries with it a series of trade-offs. We’ll cover each medium available, highlighting the advantages and disadvantages of each in addition to identifying a target environment size.

      CD/DVD Old faithful, the CD/DVD, has been around since long before ESX, and it continues on with vSphere. This is the most basic medium because it offers no updating facility. CD/DVD is most commonly used in small environments with just a handful of hosts. It is, however, the simplest, which means that anyone can leverage this method.

      Thumb Drive/USB Key The heir apparent to the optical drive, USB keys are the preferred installation medium for small/medium environments, generally those with fewer than 10 hosts. They have the inherent ability to be updated easily, and they are significantly faster than optical drives. Because they can be easily updated, they are also an excellent source for vSphere Kickstart-based installations.

      PXE The most flexible (and usually fastest) of all installs, Preboot Execution Environment (PXE) has the most complex setup. Once configured, it’s easy to maintain and update the