Automating Virtual Machine Power Management in VMware vSphere

# Install the VMware PowerCLI module if not already installed
Install-Module -Name VMware.PowerCLI -Scope CurrentUser -Force

# Connect to the vSphere server
$server = "your_vcenter_server"
$username = "your_username"
$password = "your_password"
Connect-VIServer -Server $server -User $username -Password $password

# Start or stop virtual machines based on their current state
$vms = Get-VM
foreach ($vm in $vms) {
    if ($vm.PowerState -eq "PoweredOff") {
        # Start the VM
        Start-VM -VM $vm
        Write-Host "$($vm.Name) has been started."
    } elseif ($vm.PowerState -eq "PoweredOn") {
        # Stop the VM
        Stop-VM -VM $vm -Confirm:$false
        Write-Host "$($vm.Name) has been stopped."
    }
}

# Disconnect from vSphere server
Disconnect-VIServer -Server $server -Confirm:$false