Invoke-IcingaCheckHyperVSnapshot - You cannot call a method on a null-valued expression.

[Aleksey-Maksimov]

Hello.

The snapshot checking plugin Invoke-IcingaCheckHyperVSnapshot works fine if all virtual machines are included in the scan

Invoke-IcingaCheckHyperVSnapshot -Verbosity 2 -CountSnapshotWarning 0 -NoPerfData -AvoidEmptyCheck

[OK] VM Snapshots: 4 Ok
\_ [OK] KOM-WS41
   \_ [OK] KOM-WS41
      \_ [OK] No snapshots created: 0
\_ [OK] KOM-WS42
   \_ [OK] KOM-WS42
      \_ [OK] No snapshots created: 0
\_ [OK] KOM-WS43
   \_ [OK] KOM-WS43
      \_ [OK] No snapshots created: 0
\_ [OK] KOM-WS44
   \_ [OK] KOM-WS44
      \_ [OK] No snapshots created: 0

Also, the plugin works fine if we add the -ExcludeVms filter and a certain part of the virtual machines is included in the selection

Invoke-IcingaCheckHyperVSnapshot -Verbosity 2 -CountSnapshotWarning 0 -NoPerfData -ExcludeVms "*-WS41" -AvoidEmptyCheck

[OK] VM Snapshots: 3 Ok
\_ [OK] KOM-WS42
   \_ [OK] KOM-WS42
      \_ [OK] No snapshots created: 0
\_ [OK] KOM-WS43
   \_ [OK] KOM-WS43
      \_ [OK] No snapshots created: 0
\_ [OK] KOM-WS44
   \_ [OK] KOM-WS44
      \_ [OK] No snapshots created: 0

However, if the plugin filters out all virtual machines, we will receive an error

Invoke-IcingaCheckHyperVSnapshot -Verbosity 2 -CountSnapshotWarning 0 -NoPerfData -ExcludeVms "*-WS4*" -AvoidEmptyCheck

You cannot call a method on a null-valued expression.
At C:\Program Files\WindowsPowerShell\Modules\icinga-powershell-hyperv\compiled\icinga-powershell-hyperv.ifw_compilation.psm1:785 char:9
+     if ($VirtualComputers.Summary.ContainsKey('SnapshotLocated')) {
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

[OK] VM Snapshots

We need an additional option that allows us to set the status to OK if the VMs are not selected.
Thank you.

[Aleksey-Maksimov]

Hello.

I updated the plugin to the latest version 1.3.1, but the problem remains.

Installed components on this system:
agent 2.14.4
cluster 1.3.0
framework 1.13.2
hyperv 1.3.1
plugins 1.13.0
service 1.2.0

Invoke-IcingaCheckHyperVSnapshot -AvoidEmptyCheck -CountSnapshotWarning 0 -ExcludeVms "*-WS4*" -NoPerfData -Verbosity 2

You cannot call a method on a null-valued expression.
At C:\Program Files\WindowsPowerShell\Modules\icinga-powershell-hyperv\compiled\icinga-powershell-hyperv.ifw_compilation.psm1:785 char:9
+     if ($VirtualComputers.Summary.ContainsKey('SnapshotLocated')) {
+         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

[OK] VM Snapshots
0

[adn77]

@Aleksey-Maksimov I believe you are running into the same issues as I am...

This line

icinga-powershell-hyperv/provider/vcomputer/Get-IcingaVirtualComputerInfo.psm1

Line 438 in 42ac61a

if ([string]::IsNullOrEmpty($details.Partition)) {

should fail as there is no $PhysicalDisk.DriveReference for the snapshot in question. This line works for me:

          if ([string]::IsNullOrEmpty($details.Partition) -or [string]::IsNullOrEmpty($PhysicalDisk.DriveReference) ) {

I would guess you're running your VMs on "Microsoft Storage Spaces" (no CSV), which are not listed in the regular disk views.
@LordHepipud this Icinga/icinga-powershell-plugins#390 code seems to fix the underlying issue. Unfortunately there doesn't seem to be a nice way to merge the two disk types:
Physical Disks

Get-IcingaWindowsInformation MSFT_PhysicalDisk -Namespace 'root\Microsoft\Windows\Storage'

Microsoft Storage Spaces

Get-IcingaWindowsInformation MSFT_VirtualDisk -Namespace 'root\Microsoft\Windows\Storage'

I am running a modified version incorporating those changes and could provide a PR if you see this fit.

Alex

[Aleksey-Maksimov]

We do not use "Microsoft Storage Spaces". All our virtual disks are located on a CSV volume.