This was discovered on a notebook using the Dutch 32-bits edition while copying many files over the network for a backup. It can be reproduced on a VirtualBox Virtual Machine using an English 64-bits edition of Windows 10.
How to reproduce using a VirtualBox VM:
- create a clean windows 10 guest VM
- ensure that the network adapter is using Network bridge and is useable on the Host computer
- share a directory on the guest and make sure you can access this share from the host to copy files to it
- create a mapped drive on the host to the shared directory on the guest
- add another network adapter in VirtualBox using Network bridge or Nat, leave the virtual cable disconnected
- create a network bridge on the guest using both network adapters
- the new adapter is a Microsoft Network Adapter Multiplexor, ensure the share still works
- on the host start a copy of a big directory with many files like c:\windows to the guest
- on the guest keep track of how much memory is used using Task Manager, Performance tab, Memory pane.
- keep an eye on the Paged and Non-Paged Pool values, these will slowly but steadily increase.
In my test VM, the values are:
At start: paged pool 129 MB, non-paged pool 41.1 MB.
At 20000 files, 7.4 GB copied: paged pool 161 MB, non-paged pool 125 MB.
At 30000 files, 18.1 GB copied: paged pool 173 MB, non-paged pool 236 MB.
After stopping the copy and deleting the mapped network drive the memory used for the paged and non-paged pool remain high.
If you keep copying files eventually the guest VM will start swapping memory and become unresponsive.
This problem also seems to exist on Windows 8.1. It works fine on Windows XP, I'm not sure about Windows 7.
Can someone reproduce this problem? Does an easy solution exist to fix this memory leak while keeping the functionality? Can the problem be fixed?
This question was asked previously in the Dutch forum at: