Shared folders in Linux Mint 21 VirtualBox 6.1 not working

[rburkey]

My host machine is Mint 17.3. I'm running VirtualBox 6.1.18 on it, even though the current version is 6.1.36, because that's the latest supported version of VirtualBox on Mint 17.3. Nor can I build the latest VirtualBox from source, because it requires a later version of Qt5 than Mint 17.3 uses, which requires a later version of libstdc++, and so on.

I have 4 VMs with Mint guest systems: Mint 15, Mint 19.1, Mint 20.1, and Mint 21. The latter was installed just yesterday, and the others have been in use for quite a while.

Each of the 4 VMs has an identical shared folder, with the desktop of the host.

The Mint 15, 19.1, and 20.1 shared folders all work fine.

The Mint 21 shared folder does not work at all. An entry for it shows up in /media as /media/sf_Desktop, but it appears to be simply an empty folder not attached to anything. I have added my username to to the vboxsf group on the guest. I rebooted the VM after doing so. Nothing helps.

Anything I should be doing that I haven't?

[mpack]

You don't mention installing the Guest Additions, a must if you want GA functions to work including simple Shared Folders.

Please provide a VM log file. Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

[rburkey]

Yes, the appropriate Guest Additions for 6.1.18 are installed. I've attached the zipped log. Thanks!

[rburkey]

FYI, drag-and-drop also doesn't work, although shared clipboards do. I don't really care about drag-and-drop, so I didn't think to mention it before.

[fth0]

The distance between the Linux kernels on your host and in your guest has become too big: According to the VirtualBox Changelog, Linux kernel 5.15 (on the host and in the guest) is only supported by VirtualBox 6.1.28 and newer. Linux Mint 20.1 uses Linux kernel 5.4, so you were lucky until then.

[rburkey]

It's not a big deal, since I am able to fall back on accessing the folders I want to share as network mounts, but it would still have been nice to use VirtualBox's native facility.

[rburkey]

Please provide a VM log file. Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

My apologies! I forgot that after I couldn't make shared folders work, I had disabled them in the VM's settings. I didn't think to re-enable them before posting the logfile that was requested. Here's a new logfile in which the shared folders have been enabled again. It's just as well I had forgotten anyway; for some reason the displayed log doesn't ever update unless I use the "Refresh" button, and I hadn't been aware of that.