Shared folder missing in VM alphaMELTS

[Paula]

Sometime, for examples after doing a software update for Lubuntu, your Shared folder(s) may no longer show up in VM alphaMELTS. Here are some things to try:

• If there is an update available for VirtualBox then install it would be a good idea to install it now.
• Next, confirm that you have "Automount" checked in the "Shared Folders" dialogue of VirtualBox.
• Next make sure VirtualBox Guest Additions is up to date. On the host machine find the "About VirtualBox VM" pop up (usually under "Help", but it depends on the version and operating system). Note the version / release number (e.g. "6.0.22 r137980"). Then in the alphaMELTS Ubuntu guest, open the terminal and type "modinfo vboxguest". Check that the version and r-number match.
• If you need to update the VirtualBox Guest Additions, you will need the password (which is the former name of alphaMELTS, as detailed here):
  
  • Start the alphaMELTS Lubuntu machine, if it is not already started.
  • Select 'Devices' -> 'Insert Guest Additions CD image...' in the VirtualBox menu, and click OK to open it in File Manager.
  • Select 'Tools' -> 'Open Current Folder in Terminal' from the File Manager menu.
  • Type 'sudo ./VBoxLinuxAdditions.run' (or 'sudo ./VBoxLinux' and then the tab key) and press the return key.
  • Enter the password and then wait while it removes the old version and installs the new one.
  • Finally click the 'eject' button next to the CD image in the File Manager.
• Reboot the alphaMELTS Lubuntu machine. If the Shared folder(s) are still not showing:
  
  • Open the Terminal and type "sudo systemctl edit --full vboxadd-service". Enter the password and the nano editor will oen.
  • Make sure the version number is correct near the top of the file in the "SourcePath=" line, and near the bottom not the "ExecStart=" and "ExecStop=" lines (without the release number, so you should see "VBoxGuestAdditions-6.0.2" in the paths for the example above).
  • On the "Conflicts=" line delete "systemd-timesync.service" if it is there, so that the line should read "Conflicts=shutdown.target".
  • Use Ctrl+o to save, and Ctrl+x to exit. The Shared folder(s) should be there, but if not try rebooting.
• Finally reboot alphaMELTS Lubuntu one more time to make sure that the Shared folder(s) are showing up consistently.

Hope that works!