Home > Storage > PowerVault > Guides > Dell PowerVault ME5 Series: Microsoft Hyper-V Best Practices > Trim and unmap and for space recovery
When a file is deleted on a Windows Server, the file pointer is deleted. However, the old data remains on the disk. Over time, the operating system overwrites the old data with new data.
For PowerVault volumes mapped to a Windows Server, the host passes a trim and unmap command to PowerVault when files are deleted. Within a few minutes, the PowerVault storage pool reflects the additional free capacity.
The ability to recover deleted disk space on PowerVault is a key benefit of thinly provisioned volumes. In cases where trim and unmap is not supported or disabled, reclaimed space appears as free in Windows, but not on the storage.
Windows Server and Hyper-V support trim and unmap natively with PowerVault given these conditions: