Challenge
When storage snapshot gets mounted to proxy Windows creates multiple registry records in:
HKLM\SYSTEM\ControlSet001\Enum\MPIO
HKLM\SYSTEM\ControlSet001\Enum\SCSI (when windows mpio is disabled)
The problem is that when storage snapshot gets unmounted Windows does not clean up registry records.
Eventually Windows will not boot when SYSTEM hive reaches 2GB (maximum size for system hive).
Cause
Based on Microsoft KB article it is behavior by design:
On a computer that's running Windows Server 2003 or a later version of Windows, a storage device that's connected through a fiber channel or through the iSCSI protocol may be connected for only a brief period. When a storage device is connected, Windows creates registry information for the device. Over time, the registry may contain many entries for devices that will never be used again.
Solution
Microsoft recommends using DevNodeClean utility.More Information
Applies to Windows Server 2003/2012/2016:https://support.microsoft.com/en-us/help/934234/how-to-remove-registry-information-for-devices-that-will-never-be-used
https://www.microsoft.com/en-ca/download/details.aspx?id=42286