Using FreeBSD 12.0 64-bit guest OS on a Windows 10 system.
The following packages were installed with pkg:
I created a shared folder and mounted it with mount_vboxvfs.
The shared folder was set as the root of Apache's documents.
From FreeBSD, I could easily add and edit files that would be served by the web server, Apache.
However, from the host OS side (Windows), there was an issue. I could create new files and those would be served properly. But when I edited a file, it did not update. A web browser displayed the old version. I noticed unusual behavior when trying to diagnose the issue.
Using index.html as an example:
* Editing from the guest OS worked and reloading the page in my browser showed the changes
* Editing from the host OS and reloading the page did *not* show the changes
From the guest OS, I tried:
1. cat index.html: This showed the changes but a page reload still did not show them
2. vi index.html: I could see the changes. I did not make further changes and quit without saving. Reloading the page showed the old version
3. nano index.html: Once again, I could see the new version. I closed without saving but this time, reloading the page *did* show the new version
I repeated this several times. Loading the page with nano (but not making changes or re-saving) always resulted in the web page being updated the next time I hit refresh in the browser. "cat" and "vi" did not affect anything.
So, there seems to be some problem. I suspect it has to do with the guest utilities because of the very strange behavior exhibited in the cat, vi, nano tests.