In my last post, The Migration From ESX to ESXi is Happening. Moving Configurations, I talked about the need to move from ESX to ESXi and some of the options that came along with it. Here we are, almost a month later, and I have started to take my production environment from ESX to ESXi. Here's what I've learned in the process.
Forget keeping your current ESX profile. It doesn't matter if you have Host Profiles, or if you had an old kickstart script. Toss them out the window. Host Profiles based on ESX are going to take into account security profiles which are no longer necessary, and with 4.1 adding new features, they won't be a part of the new host. I've built a sample ESXi 4.1 kickstart script and found out first hand alot of things that were possible with ESX aren't there with ESXi.
As of vSphere 4.1, ESXi now has the ability to perform a kickstart installation, whereby you create a script to configure your ESXi host during the install. Using a kickstart script, you can get an ESXi host up and functional within a matter of a few minutes. The fact that it's functional, doesn't mean it's fully configured. Kickstart scripts are still very limited and can't completely configure your ESXi host with all that vSphere 4.1 offers. Some features that can't be scripted (atleast in my own testing) are Local Active Directory integration, prompting a user for input to create a dynamic script, simply adding a host to vCenter, configuring a Distributed Virtual Switch (dVS) because it's not a part of vCenter, and more. This might be only temporary because Justin Guidroz has created a script to add your ESXi Host to vCenter Using MOB as part of a kickstart.
I've tried going the Host Profiles route as well and not sure if I found a bug or not. I ran my sample ESXi 4.1 kickstart script and fully configured my ESXi host w/ Local AD integration, syslogging, dVS, etc. I created an ESXi host with only the Management Network configured. I added that host to vCenter and attached the Host Profile. I ran a compliance check against the host and it came back saying all kinds of parameters were not in compliance. I went ahead and applied the profile to the host. I was prompted to enter IP addresses for all of my vmknics, and then I was prompted to enter my Active Directory credentials, I clicked Join Domain, and then it died. I couldn't click on Next or Previous, the only option that I could click was Cancel. The ESXi host never joined the domain because the machine was never populated within Active Directory. I tried entering my credentials in two ways DOMAIN/user and user@domain, both yielded the same results. I figured it was an AD problem. I went directly to the host and joined it to the domain using Configuration -> Authentication Services. I rescanned the host for compliance and verified that Active Directory services were no longer out of compliance. I tried re-applying the profile to the host and I'm still prompted to enter my AD credentials, ultimately leaving me at the same result as before. I created a service request yesterday, we'll see what happens.
Another issue I have about Host Profiles is their negligence for jumbo frames. If you create a vmknic or vSwitch with MTU 9000, that configuration is not taken into account when applying the profile. For everyone using IP-based storage and jumbo frames, make sure to configure all of this using the kickstart or PowerCLI.
If you're into spending some cash, take a look at vProfile Configuration Management from Reflex Systems. When I talked to an SE at vForum in Cincinnati, he told me that this product took into account anoother 130 or so parameters than vSphere's Host Profiles. I don't know if they support jumbo frames or even all 4.1 features yet, but it's an option.
PowerCLI is going to be one of the best ways to round-out a fully configured ESXi host. You can get the base work done using a kickstart script, but for everything that can't be done, PowerCLI is there. PowerCLI has cmd-lets for anything you do within vCenter or directly to your hosts. If you aren't a PowerCLI guru, myself included, take a look at Onyx from VMware Labs. Think of Onyx as a proxy between the vSphere Client and vCenter. Once it's all configured, anything you are doing within the vSphere Client is automatically being translated into a PowerCLI script that you can copy and paste and hack around with until you get it to your liking. So after you get done with your kickstart script use a PowerCLI script to take care of the rest.
Really, there isn't any one good way to transfer an existing ESX profile. Count on building from scratch. Rick Vanover made a good point, stating that you need to have enough capacity to facilitate some downtime of a host or two while you make these upgrades. Take a few of the methods above and get your ESXi deployments to a point where you can be lazy once again.