[Unmount and Detach Datastore from ESXi Host] #PowerCLI

mount_unmount.ps1

$esx = Get-VMHost *esx01*
$ds = Get-Datastore -VMHost $esx
$lun = Get-ScsiLun -VmHost $esx 
$hostStorageSystem = Get-View $esx.Extensiondata.ConfigManager.StorageSystem


foreach ($uuid in $ds.ExtensionData.info.Vmfs.uuid)
{
    Write-Host -ForegroundColor Magenta "Unmounting Volume $uuid"
    $hostSTorageSystem.UnmountVmfsVolume($uuid)
}

foreach ($uuid in $lun.CanonicalName)
{
    Write-Host -ForegroundColor Green "Detaching Lun $uuid"
    $hostStorageSystem.DetachScsiLun($uuid)    
}


foreach ($uuid in $lun.CanonicalName)
{
    Write-Host -ForegroundColor Green "Attaching Lun $uuid"
    $hostStorageSystem.AttachScsiLun($uuid)    
}

Get-VMHostStorage -RescanAllHba -RescanVmfs -VMHost $esx

foreach ($uuid in $ds.ExtensionData.info.Vmfs.uuid)
{
    Write-Host -ForegroundColor Magenta "Mounting Volume $uuid"
    $hostSTorageSystem.MountVmfsVolume($uuid)
}