Do you need to modify large number of disk classifications in System Center Virtual Machine Manager (SCVMM)? It is very simple in PowerShell.

Get-SCVMHost -VMMServer MyVMMserver -ComputerName MyHyperV -OutVariable vmHost |
    Format-Table -Property FQDN, ProcessorModel

$storageClassification = Get-SCStorageClassification -Name 'My disk class'
Get-SCStorageDisk -VMHost $vmHost[0] -OutVariable hostDisk | Format-Table -Property Name, Classification
$hostDisk | Set-SCStorageDisk -StorageClassification $storageClassification | Format-Table -Property Name, Classification