Get-Tag; Get-TagAssignment - Tag Commands from Powershell/PowerCLI are very slow on VMs with no tag - Workarounds or Bug?

[NellaSenoj]

Summary:

I am using the PowerCLI plugin to PowerShell to perform repetitive actions on a 6.7 vCenter that include Get-Tag and Get-TagAssignment. The environment I administrate is thousands of VMs over 100+ hosts and when processing some VMs the tag commands can take > 60 seconds and in some cases several minutes to perform a simple assignment lookup on a single VM.

Question:

Is there a known issue (I've searched and seen many posts from years gone by on this) with a bug track or is there a workaround that can reduce the time for these actions?

Other Details:

My script is designed to make the fewest calls necessary after extensive Get-VM/Get-View filtering. I have verified the Tag commands are where the delays are coming from by using PS Write-Progress statements in front of the commands. After several runs I did note that VMs that do have a vCenter tag assigned process quickly and VMs that do not have a vCenter tag assigned are showing the delay. I have also tried using the community Powershell plugin: rCisTag and rCisTagAssignment which are showing the same behavior which suggests the API is a factor?

[LucD]

The Tag related cmdlet are known to be very time-consuming.
The latest PowerCLI releases have introduced some improvements to that.

Which PowerCLI version are you using?

Would you care to share your code?
There might be some improvements possible.

[NellaSenoj]

Powershell VMware Modules/Versions:

PS C:\Scripts> Get-Module VMware* -ListAvailable | Select Name,Version

Name                                    Version       

----                                    -------       

VMware.Community.CISTag                 1.0.0         

VMware.CloudServices                    12.0.0.15947289

VMware.DeployAutomation                 7.0.0.15902843

VMware.ImageBuilder                     7.0.0.15902843

VMware.PowerCLI                         12.0.0.15947286

VMware.Vim                              7.0.0.15939650

VMware.VimAutomation.Cis.Core           12.0.0.15939657

VMware.VimAutomation.Cloud              12.0.0.15940183

VMware.VimAutomation.Common             12.0.0.15939652

VMware.VimAutomation.Core               12.0.0.15939655

VMware.VimAutomation.Hcx                12.0.0.15939647

VMware.VimAutomation.HorizonView        7.12.0.15718406

VMware.VimAutomation.License            12.0.0.15939670

VMware.VimAutomation.Nsxt               12.0.0.15939671

VMware.VimAutomation.Sdk                12.0.0.15939651

VMware.VimAutomation.Security           12.0.0.15939672

VMware.VimAutomation.Srm                11.5.0.14899557

VMware.VimAutomation.Storage            12.0.0.15939648

VMware.VimAutomation.StorageUtility     1.3.0.0       

VMware.VimAutomation.Vds                12.0.0.15940185

VMware.VimAutomation.Vmc                12.0.0.15947287

VMware.VimAutomation.vROps              12.0.0.15940184

VMware.VimAutomation.WorkloadManagement 12.0.0.15947288

VMware.VumAutomation                    6.5.1.7862888

As to the code, the relevant command (below) is part of the scriptblock from an "If" statement (limiting the call on an as-needed basis) after which the $VMTags array is parsed for specifics:

$VMTags = Get-VM $VM | Get-TagAssignment | Where {($_.Tag -like "Domain*") -or ($_.Tag -like "Custom*")}

In my testing, I put a "Write-Progress" statement in front of this command to track which $VM objects were stalling. As noted in the OP I also tried the Get-rCisTagAssignment community module and noted the same stalling behavior on $VM objects that did not have a tag.

Again, to me this seems more like an API problem than a Powershell/PowerCli issue..

[LucD]

You have the latest PowerCLI version, that is good.

And yes, as I mentioned earlier, the Tag related cmdlets are notoriously slow.

And indeed, that is most probably due to the internal Tag handling code, and not PowerCLI.