To validate the connectivity to Hyper-V hosts using PowerShell and attempt to reconnect in case of disconnection, you can use the following script. This script will check the connectivity to the specified Hyper-V hosts, and if any host is found to be disconnected, it will attempt to reconnect and display the error message in case of a disconnection.

# Replace 'HyperVHost1', 'HyperVHost2', etc., with the actual names or IP addresses of your Hyper-V hosts.
$HyperVHosts = @('HyperVHost1', 'HyperVHost2', 'HyperVHost3')

# Function to test the connectivity to a Hyper-V host
function Test-HyperVHostConnection {
    param (
        [string]$Host
    )
    try {
        # Test the connectivity to the Hyper-V host
        $result = Test-Connection -ComputerName $Host -Count 1 -Quiet
        if ($result) {
            Write-Host "Connected to $Host."
        } else {
            Write-Host "Disconnected from $Host."
            $false
        }
    }
    catch {
        Write-Host "Error occurred while testing the connection to $Host: $_"
        $false
    }
}

# Function to reconnect to a Hyper-V host
function Reconnect-HyperVHost {
    param (
        [string]$Host
    )
    try {
        # Reconnect to the Hyper-V host
        Write-Host "Reconnecting to $Host..."
        Connect-VIServer -Server $Host -ErrorAction Stop
        Write-Host "Reconnected to $Host successfully."
        $true
    }
    catch {
        Write-Host "Error occurred while reconnecting to $Host: $_"
        $false
    }
}

# Main script
try {
    foreach ($host in $HyperVHosts) {
        if (!(Test-HyperVHostConnection -Host $host)) {
            # Attempt to reconnect if the host is disconnected
            if (Reconnect-HyperVHost -Host $host) {
                # Perform any additional operations needed after a successful reconnection.
                # For example, you could list VMs, get their status, etc.
                # Get-VM -VMHost $host
            }
        }
    }
}
catch {
    Write-Host "Script encountered an error: $_"
}

In this script, we first define an array $HyperVHosts with the names or IP addresses of the Hyper-V hosts you want to test. The script then contains two functions:

1. Test-HyperVHostConnection: This function tests the connectivity to a Hyper-V host using the Test-Connection cmdlet. If the test succeeds, it displays a message indicating that the host is connected. If the test fails, it displays a message indicating that the host is disconnected.
2. Reconnect-HyperVHost: This function attempts to reconnect to a disconnected Hyper-V host using the Connect-VIServer cmdlet from PowerCLI. If the reconnection is successful, it displays a message indicating that the host was reconnected.

The main script iterates through the list of Hyper-V hosts, tests their connectivity, and attempts to reconnect if disconnected. If any errors occur during the connectivity test or reconnection process, the script will display the error message.

Please ensure you have the appropriate permissions to connect and manage Hyper-V hosts, and also make sure you have PowerCLI installed and properly configured before running the script.

To perform Hyper-V checks on an SMB (Server Message Block) share and log any errors to a file using PowerShell, you can follow these steps and use the examples provided below:

1. First, ensure you have the Hyper-V PowerShell module installed. If it’s not already installed, you can install it using the following command:

Install-WindowsFeature -Name Hyper-V-PowerShell

2. Next, you need to set up the SMB share and grant the necessary permissions to the Hyper-V hosts. Ensure that the Hyper-V hosts have read and write access to the share.
3. Create a PowerShell script that performs the Hyper-V checks on the SMB share and logs any errors to a file. Here’s an example script:

# Define the SMB share path
$SMBSharePath = "\\server\share"

# Define the log file path
$LogFile = "C:\Path\To\Log\HyperVChecks.log"

# Function to log errors to a file
function Log-Error {
    param(
        [string]$ErrorMessage
    )
    $Timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    $ErrorMessage = "$Timestamp - $ErrorMessage"
    Add-Content -Path $LogFile -Value $ErrorMessage
}

# Function to perform Hyper-V checks on SMB share
function Test-HyperVOnSMB {
    param (
        [string]$SMBSharePath
    )
    try {
        # Check if Hyper-V is installed on the local machine
        if (-Not (Get-WindowsFeature -Name Hyper-V | Where-Object { $_.Installed })) {
            throw "Hyper-V is not installed on this machine."
        }

        # Test if the SMB share is accessible
        $TestFile = "$SMBSharePath\HyperVCheckTestFile.txt"
        New-Item -ItemType File -Path $TestFile -ErrorAction Stop
        Remove-Item -Path $TestFile -ErrorAction Stop

        # All checks passed, return success
        return $true
    }
    catch {
        # Log the error and return failure
        Log-Error -ErrorMessage $_.Exception.Message
        return $false
    }
}

# Execute the Hyper-V checks on SMB share
$result = Test-HyperVOnSMB -SMBSharePath $SMBSharePath

# Display the result
if ($result) {
    Write-Host "Hyper-V checks on SMB share succeeded."
} else {
    Write-Host "Hyper-V checks on SMB share failed. Check the log file for details."
}

In the script above, we define the SMB share path and the log file path. The Test-HyperVOnSMB function checks if Hyper-V is installed on the local machine and if the SMB share is accessible. If any error occurs during the checks, the error message is logged using the Log-Error function.

Please modify the $SMBSharePath and $LogFile variables in the script to match your environment. Also, ensure that the user running the script has the necessary permissions to access the SMB share and write to the log file.

Save the script with a .ps1 extension (e.g., HyperVChecks.ps1). To run the script, open a PowerShell window and navigate to the directory where the script is saved. Then, execute the script by typing:

.\HyperVChecks.ps1

The script will perform the Hyper-V checks on the specified SMB share and log any errors to the specified log file. If the checks are successful, it will display a success message; otherwise, it will prompt you to check the log file for details.