virtualbox.org

Running Windows 2012R2 Guest server on a Ubuntu 16.04.1 server.
Today I discovered that a vital directory on the windows server, suddenly was empty. There was no obvious reason for this, so in shear frustration I rebooted the guest. This made the entire content re-appear and everything worked as it should.

Any idea how this happens, and how to avoid it? It makes it difficult to run 24/7 services when the guest doesn't run reliably.

mrwee wrote:a vital directory on the windows server, suddenly was empty

I can't think of a single reason why what you're describing doesn't sound like hocus pocus. If the directory was local (not a network share or a VirtualBox shared folder) there's no way that VirtualBox could know about even its existence. VirtualBox doesn't know about the guests' contents.