Werk #19577: hyperv_host: Fix empty vhd, vsan, nic and integration service counts for single-item VMs

Component	Checks & agents
Title	hyperv_host: Fix empty vhd, vsan, nic and integration service counts for single-item VMs
Date	Jul 9, 2026
Level	Trivial Change
Class	Bug Fix
Compatibility	Compatible - no manual interaction needed
Checkmk versions & editions	3.0.0b1 Not yet released Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT 2.5.0p10 Not yet released Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

The Windows Hyper-V host agent plugin (hyperv_host.ps1) reports, for each virtual machine, the number of virtual hard disks, virtual SANs, network adapters, integration services and VM group memberships. When a virtual machine had exactly one of these items, the reported count was empty instead of 1.

The agent executes plugins with Windows PowerShell 5.1. Unlike PowerShell 7, it does not expose a .Count property on a scalar value, and a cmdlet such as Get-VMHardDiskDrive returns a bare object rather than a collection when only a single item exists. The affected output lines therefore emitted no number.

The collections are now wrapped in an array subexpression, so a correct count is produced for single-item and multi-item virtual machines alike, on both PowerShell versions.

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