Further to my previous comment #21 above, I have found a workaround to get the shared folders working again with the latest image. It appears that the problem is with the virtualbox-guest-utils package included in the image.
Here are the steps that I performed in order to get a virtualbox ubuntu/focal64 guest with shared folders working again: Notes: It is OK to use the latest "ubuntu/focal64" box version - this was tested on 20210803.0.0 In order to be able to Insert the Guest Additions CD image, make sure you have gui enabled in Vagrantfile as per: https://www.vagrantup.com/docs/providers/virtualbox/configuration#gui-vs-headless vagrant halt # With the guest powered off, in Virtualbox in the storage settings, add an IDE Optical drive. Select the Guest Additions CD image if already available. vagrant up # click on Device -> insert Guest Additions CD image (or select it, if available, when adding the optical drive) vagrant ssh # into guest machine # then in guest machine... sudo apt-get remove virtualbox-guest-utils sudo apt update sudo apt upgrade # inspired by: http://en.ig.ma/notebook/2012/virtualbox-guest-additions-on-ubuntu-server sudo apt-get install -y dkms build-essential sudo mount /dev/cdrom /mnt sudo /mnt/VBoxLinuxAdditions.run exit # On host machine: vagrant reload # If all went well, the shared folders will now be working again. Disable gui in Vagrantfile if no longer needed dmesg on guest now shows: [ 11.087117] vboxvideo: loading version 6.1.22 r144080 [ 11.131885] 01:43:34.944899 main VBoxService 6.1.22 r144080 (verbosity: 0) linux.amd64 (Apr 28 2021 18:43:39) release log 01:43:34.944901 main Log opened 2021-08-08T01:43:34.944892000Z [ 11.131917] 01:43:34.944972 main OS Product: Linux [ 11.131929] 01:43:34.944987 main OS Release: 5.4.0-80-generic [ 11.131940] 01:43:34.944998 main OS Version: #90-Ubuntu SMP Fri Jul 9 22:49:44 UTC 2021 [ 11.131956] 01:43:34.945009 main Executable: /opt/VBoxGuestAdditions-6.1.22/sbin/VBoxService 01:43:34.945009 main Process ID: 899 01:43:34.945010 main Package type: LINUX_64BITS_GENERIC [ 11.133106] 01:43:34.946143 main 6.1.22 r144080 started. Verbose level = 0 [ 11.137611] 01:43:34.950642 main vbglR3GuestCtrlDetectPeekGetCancelSupport: Supported (#1) [ 17.071954] vboxsf: g_fHostFeatures=0x8000000f g_fSfFeatures=0x1 g_uSfLastFunction=29 [ 17.072174] *** VALIDATE vboxsf *** [ 17.072181] vboxsf: Successfully loaded version 6.1.22 r144080 [ 17.072233] vboxsf: Successfully loaded version 6.1.22 r144080 on 5.4.0-80-generic SMP mod_unload modversions (LINUX_VERSION_CODE=0x5047c) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1873506 Title: ubuntu/focal64 fails to mount Vagrant shared folders To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/1873506/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs