An interesting question on the VMTN forum caught my eye today, which was around configuring ESXi's Power Management Policy using the command-line via a kickstart script. I found this question to be interesting as I never had to tweak this configuration and was curious myself to see how you might be able to perform this via the command-line as I never recall seeing a command relating to the power management settings.

After a few minutes of digging, I found that the standard set of CLI's such as ESXCLI, vim-cmd, etc. do not provide a way to configure ESXi's power management settings but did find it was possible using my other favorite "not officially supported" CLI called vsish. Now, you can of course create a remote script using the vSphere API to configure this setting, but if you are looking to modify this within a kickstart script, this is route you will want to take.

UPDATE (01/12/15) - I just found out today from Engineering that it is possible to configure ESXi power management policy using ESXCLI. Though the parameters are currently set to hidden, you can use the following command to set the appropriate policy based on your enviornment.

esxcli system settings advanced set --option=/Power/CpuPolicy --string-value="High Performance"

UPDATE (11/04/14) - It turns out configuration changes made directly through vsish do not persist after a reboot, this might be problematic for most of you 😉 Luckily, Alan Castonguay who works in our GSS organization reached out and created a nice pyvmomi (vSphere SDK or Python) script that can be executed in the ESXi shell and of course it can easily be integrated into a Kickstart script. I have tested his sample script to verify its functionality and have also checked it into my Github repository so that others can benefit from. You can download the script which I have named configure_esxi_power_policy.py

If you run the script without any arguments, it will display the current power policy that has been enabled as seen in the screenshot below:

To change the policy, you will need to specify the "shortName" power policy, in this example I want to change it from "static" to "low":

To check whether your ESXi host supports power management, run the following command:

~ # vsish -e get /power/hardwareSupport
Hardware power management support {
CPU power management:Enhanced Intel SpeedStep(R)
Memory power management:Not available
}

To view the current power management setting, run the following command:

~ # vsish -e get /power/currentPolicy
Host power management policy {
ID: 2
Short name:dynamic
Long name:Balanced
Description:Reduce energy consumption with minimal performance compromise
}

Just like the vSphere Client, you have 4 options which maps to the "ID" property as seen above. You can get more details by querying each of the policy (1-4), here is an example:

~ # vsish -e get /power/policy/1
Host power management policy {
ID: 1
Short name:static
Long name:High Performance
Description:Do not use any power management features
}

Here's a quick table that maps the policy ID to power management policy which is the same order as shown in the vSphere Client:

To change the power management policy, run the following command:

~ # vsish -e set /power/currentPolicy 1

So now you can integrate power management settings in your ESXi kickstart script for automated deployment and configurations!