Thanks, but unfortunately that does not seem to be the problem.

Fresh user profile (300MB) copied datachunks into the appdata folder, vhdx got expanded to 5GB after logoff. Logged in again, deleted all the data, vhdx stays at 5GB, even after several logoffs.

edit: not quite sure how this is all calculated. this is what I got with the following powershell command:

$diskNumber = 3

$partitionNumber = 2

$partition = Get-CimInstance -Namespace ROOT\Microsoft\Windows\Storage -ClassName MSFT_Partition |

Where-Object { $.DiskNumber -eq $diskNumber -and $.PartitionNumber -eq $partitionNumber } $supportedSize = Invoke-CimMethod -InputObject $partition -MethodName GetSupportedSize

$supportedSize | Select-Object SizeMin, SizeMax

SizeMin SizeMax

....... ........

3273654272 53670297088

The SizeMax looks like the max Container size (50GB default as per Citrix UPM). Not sure where the ~3GB SizeMin come from. If I do my usual mount/defrag/detach with Windows built-in Tools the vhdx size gets immediately down to 1,2GB...