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Did you know that VMware Host Profile is extensible by 3rd Parties?

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Managing ESXi host configurations can be challenging and the potential risk for configuration drift between the running environment and the set of configuration scripts or worse, manual configuration is quite high. On top of that, how do you ensure proper compliance of all your ESXi host configurations in your environment and easily prove that in an internal or security audit?

This is where VMware Host Profile can help which allows administrators to capture the running configurations of an ESXi host and automatically creating a template (Host Profile) that can then be applied across new or existing ESXi hosts. By leveraging Host Profile, administrators can ensure that all their ESXi host configurations are always consistent and configuration drifts can easily be prevented through automatic compliance checks.

Recently, while searching for something on VMware's HCL website, I accidentally stumbled onto what appears to be 3rd party Host Profiles? There were only two listed, one from Brocade for managing and configuring Brocade storage adapters and the other from Dell for managing and configuring Dell's EqualLogic MEM (Multipathing Extension Module). I was actually quite surprise to learn about these custom 3rd party Host Profiles. In doing a bit of digging and research it turns out that VMware Host Profile are in fact extensible by design, which was something new to me.

Note: For a technical overview of Host Profile, you can take a look at this whitepaper here. 

Host Profile Architecture

Host Profile was first introduced with the release of vSphere 4.1 and the brain of the system is known as the Host Profile Engine which was part of the vCenter Server. In vSphere 5.0, Host Profile was re-architected and the Host Profile Engine was moved into the ESXi host which allowed for Host Profile Plugins to be added to an ESXi Image and expose new Host Profiles through the Host Profile Engine.

A Host Profile is actually a hierarchical composition of multiple sub-profiles and policies. Each policy defines a set of parameters that a user can select from and apply to an ESXi host. For instance, the default VMware Host Profile is composed up of 12 individual sub-profiles: authentication, datetime, firewall, memory, network, option, security, service, storage, userAccount and userGroupAccount.

With this new re-architecutre, Host Profile can be extended by 3rd party partners/vendors to create custom Host Profile Plugins to expose vendor specific hardware or software configurations and made available through a common Host Profile API/UI for customers to consume.

Host Profile Extensibility Options

To build a Host Profile Plugin, you will need to use the Host Profile SDK which is only available as part of VMware TAP (Technology Alliance Partner) Program. A Host Profile Plugin basically wraps the actual configuration work and can be backed by one of three ways:

  1. CIM Provider using the CIM SDK
  2. ESXCLI plugins
  3. Userworld binaries

As you can see, creating a Host Profile Plugin is quite flexible and can be exposed through several mechanisms. The most shocking discovery that I found was the lack of 3rd party vendor Host Profiles that exists today, especially from the big server hardware vendors. Coming from a Systems Administrator background, I would loved to have been able to configure and manage my server's firmware, BIOS, out-of-band management (iLO/DRAC), etc. through either a custom ESXCLI plugin or Host Profile Plugin. This would really benefit customers from having to manage configurations using multiple tools and allowing them centralize their management including compliance capabilities all from a single interface.

Hopefully this was an educational post for everyone and if you are a customer and would like to see certain functionality exposed by our 3rd party partners, feel free to leave a message and perhaps one of them may consider adding a custom Host Profile Plugin 🙂

Quick Tip - How to Change ESXi SSH Prompt

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This quick tip was motivated by a comment from Jason Nash where he wished the hostname of an ESXi host is automatically displayed on the SSH prompt when logging into the system. Traditionally, systems providing SSH access will default the SSH prompt to use the format of [username@hostname current-working-directory], but for an ESXi host, it just displays the current working directory.

This is not that big of an issue, unless you have multiple connections opened up to various systems which is usually the case for the average System Administrator. Being able to quickly identify the host you on are without having to run the hostname command would be nice and I can see why Jason would want to have this. Having said that, this is something you can easily configure on ESXi as well as other UNIX/Linux system in terms of customizing the SSH prompt.

To change the SSH prompt on ESXi, you will need to edit /etc/profile.local configuration file and add PS1 environmental variable which controls the SSH prompt. The configuration file is automatically backed up and all changes will persist through a reboot.

If you want to enable the basic [username@hostname current-working-directory], add the following to the file:

PS1="[\u@\h:\w] "

Now when you login to your ESXi host, the SSH prompt will look like this:

You can even add colors to your SSH prompt, if you add the following to the file:

PS1="\e[0;41m[\u@\h \W]\$ \e[m"

It will look like this:

The above are just examples of the customization you can apply to the SSH prompt, for more options you can take a look at this reference or search for others online. You can also quickly test your changes by just setting the PS1 variable on the command-line and then logging in.

Since this is something that has annoyed me from time to time, I will be filing a Feature Request with engineering and hopefully we can have this as a default in the future. Thanks Jason for bringing this up!

How to run Nested RHEV Hypervisor on ESXi?

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I have written a number of articles about VMware Nested Virtualization and even today, I am still surprised at how easy it is to virtualize not only our own hypervisor but other vendor's hypervisors as well. This week I received an interesting question from my old Technical Marketing colleague Rawlinson Rivera who wanted to run a nested RHEV (Red Hat Enterprise Virtualization) Hypervisor on ESXi. This was not something I had done before nor had any interest in doing and I told Rawlinson that it should technically work as long as the guestOS is enabled with VHV.

Rawlinson's attempt at installing RHEV resulted in the VM hanging after boot up. After a bit of research, it turns out some additional tweaks are required to get RHEV running on ESXi. I would like to give a huge thanks to Jim Mattson, one of the VMware developers who help made Nested Virtualization possible, for his assistance.

Disclaimer: This is not officially supported by VMware. Please use at your own risk.

Here are the instructions on creating a virtual machine that can be used to install RHEV (make sure you follow these exact steps, the VM must be created with these settings or it will not work):

Step 1 - Download RHEV 6.3 or 6.4 from Red Hat's website

Step 2 - Create a new Virtual Machine (vHW9) and when you get to the OS selection, you will need to select the following:

Guest Family - Other
Guest Version - Other (64-bit)

Step 3 - When you get to the virtual hardware customization, make sure you select LSI Logic SAS for the SCSI controller and also enable VHV under the CPU option.

Step 4 - Finally, you will need to add the following two advanced virtual machine settings:
vcpu.hotadd = false
apic.xapic.enable = false

Step 5 - Mount the RHEV ISO and once the VM starts to boot up, when you are presented with install/upgrade options, hit the TAB key. This will allow you to change the boot parameters and you will need to move your cursor to the left and remove "quiet" from the command-line which is right after the install keyword and then hit enter.

Note: This is required due to a known issue from Red Hat.

Step 6 - If everything was successful, you should be prompted with RHEV installer:

Step 7 - Once the installer has completed and you reboot, you now have nested RHEV running on ESXi!

Now it is time to delete the VM 😉