Slow-Loading Modules

Two related questions:

I have two PS scripting hosts (test/prod). On the test system, loading a particular module takes ~1.25-1.4 seconds. On the prod system, however, loading the same module took nearly a minute and a half.

Looking into differences, the only thing we could find is that the test system was a public IP and our prod system is private IP (no external network access). So doing a little digging and netstat, we found that it was spending a long time trying to contact akamai. We finally realized that it was checking the publisher certificate revocation. So we disabled ‘Check for publisher’s certificate revocation’ in Control Panel\Internet Options\Advanced and it reduces the module load time. However, it doesn’t reduce it to just the ~1 second. It still takes ~15-20 seconds.

So #1, any further ideas or recommendations on how to diagnose significantly slow module loading times?

Secondly, in trying to reduce this load time, I started looking at module auto-loading. Since PSv4, I was under the impression that when a cmdlet was executed that existed in a module that sits in the $Env:PSModulePath, that PS would load the module at execution time. However, despite having $PSModuleAutoLoadingPrference = “All” in my profile (C:\Users[username]\Documents\Profile.ps1), it will fail to load the module.

PS> $Env:PSModulePath
C:\Users\[username]\Documents\WindowsPowerShell\Modules;C:\Program Files\WindowsPowerShell\Modules;C:\Windows\system32\WindowsPowerShell\v1.0\Modules;C:\Program Files (x86)\VMware\Infrastructure\vSphere PowerCLI\Modules

PS> Get-Module -ListAvailable
    Directory: C:\Program Files (x86)\VMware\Infrastructure\vSphere PowerCLI\Modules
ModuleType Version    Name                           ExportedCommands
---------- -------    ----                           ----------------
Binary    VMware.VimAutomation.Cis.Core
Binary    VMware.VimAutomation.Cloud
Manifest    VMware.VimAutomation.Common
Manifest    VMware.VimAutomation.Core

PS> $PSModuleAutoLoadingPreference
PS> Connect-VIServer
Connect-VIServer : The term 'Connect-VIServer' is not recognized as the name of a cmdlet, function, script file,....

PS> Import-Module VMware.VimAutomation.Core
PS> Connect-VIServer
Supply values for the following parameters:....

So #2, is there something else required in order to have PS auto-load a module when I use a cmdlet found within it? Is the fact that the ‘ExportedCommands’ appear empty have anything to do with it?

NOTE: I’d prefer to avoid putting explicit Import-Module calls into the profile if possible. These modules are not used everytime and I’d like to avoid loading them if I can.

Thank you for any insight.

if you use PowerCli version lower than 6.5 it not fully modularized, it still use snapins. try to upgrade

To answer the auto-load question, see this:

Starting in Windows PowerShell 3.0, installed modules are automatically imported to the session when you use any commands or providers in the module. However, you can still use the Import-Module command to import a module and you can enable and disable automatic module importing by using the $PSModuleAutoloadingPreference preference variable. For more information about modules, see about_Modules ( For more information about the $PSModuleAutoloadingPreference variable, see about_Preference_Variables (

@Max, thank you for the recommendation. I did update to 6.5, and while ‘HookGetViewAutoCompiler’ now appears in the VMware.VimAutomation.Core ‘ExportedCommands’, it still doesn’t auto-load any of the cmdlets.

@Rob, I appreciate the link, but if you see in my command block, I do have the $PSModuleAutoloading set to ‘All’ and also Import the module manually when auto-loading fails.

So I am still struggling to understand why it fails.

I think this is because of PowerCli module structure
there is no exported commands which PS can use for autoloading

    Directory: C:\Program Files (x86)\VMware\Infrastructure\PowerCLI\Modules

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Binary    VMware.DeployAutomation
Binary    VMware.ImageBuilder
Binary VMware.VimAutomation.Cis.Core
Binary VMware.VimAutomation.Cloud
Manifest VMware.VimAutomation.Common
Binary VMware.VimAutomation.Core           HookGetViewAutoCompleter
Binary    VMware.VimAutomation.HA
Binary VMware.VimAutomation.HorizonView
Binary VMware.VimAutomation.License
Binary VMware.VimAutomation.PCloud
Manifest VMware.VimAutomation.Sdk            Get-PSVersion
Binary VMware.VimAutomation.Storage
Binary VMware.VimAutomation.Vds
Binary VMware.VimAutomation.vROps
Binary    VMware.VumAutomation

I’m personally prefer to use oneliners and have Import-Module VMware.VimAutomation.Core in my profile
but also I have #require -module VMware.VimAutomation.Core in my scripts