virtualbox.org

I recently upgraded a Debian guest from 7 (wheezy) to 8 (jessie).

I can successfully mount shared folders like so: But I am unable to unmount them: I also tried with option "-t vboxsf" but same result. Any ideas as to cause?

Some stuff which might be relevant:
VirtualBox Version 5.0.10 r104061
I had to reinstall guest additions.
At boot time I see the message "failed to start vboxadd-service.service" and syslog shows:

It appears you are using automount and as such the share is considered removable media and not a mount/umount device. Either shut down the guest and remove the share than create the share *not automount and use the mount/umount in the guest or reboot the guest to refresh the automount share.

Thanks for the suggestion but no, I'm mounting manually, so I don't think that can be it. Maybe you thought that because I was mounting under /media?

Anyway, just to be sure, I shut down the guest, removed the shared folder and re-created it in the VB manager (making sure not to tick the automount option), rebooted the guest and manually mounted under /mnt. Same behaviour as before; I cannot unmount. (I also looked for /etc/auto.* config files on the guest, to see if I could spot anything suspicious, but there are none.)

Post the guests log file ( as an attachment ). Right click on the guest in the Main Manager then click show log. Save and post as an attachment. Compress if it is too large to post.

Attached as requested.

Log shows a good share and that it is accepted. This is going to point at the guest.

Your umount statement "umount.nfs: /media/sf_seb: is not an NFS filesystem" looks suspicious to me. I would look at the dmesg and syslog of the guest to make sure that the vboxsf service is actually loading. You can also look at the /var/log/vboxadd-install.log for answers as to whether the guest additions installed correctly.

The install log looks good (attached).
dmesg looks good (attached).
But there are some troublesome looking messages in syslog (attached), in particular:

Dec 4 15:39:02 bigears vboxadd[595]: Starting the VirtualBox Guest Additions ...done.
Dec 4 15:39:02 bigears kernel: [ 18.216101] vboxsf: Successfully loaded version 5.0.10 (interface 0x00010004)
Dec 4 15:39:02 bigears saned[689]: saned disabled; edit /etc/default/saned.
Dec 4 15:39:02 bigears vboxadd-service[701]: Starting VirtualBox Guest Addition service ...done.
Dec 4 15:39:02 bigears systemd[1]: vboxadd-service.service: control process exited, code=exited status=1
Dec 4 15:39:02 bigears systemd[1]: Failed to start vboxadd-service.service.
Dec 4 15:39:02 bigears systemd[1]: Unit vboxadd-service.service entered failed state.

Any suggestions?

I would purge VirtualBox from the guest, reboot, and install a fresh copy. I have seen a corrupt install when upgrading a distro before. Normally I install a new instance and keep all data on a second partition so it is retained. I also set the home folder to a separate partition so all of my configurations are retained.

Could you amplify a bit what you mean by "purge VirtualBox from the guest"? I uninstalled the guest additions by running and then reinstalled, but it made no difference. I'm guessing you mean something more comprehensive.

You need to uninstall like you did and then check to see if there are any other versions or remnants of older installs. I normally do this from CLI and use apt-get purge ... to make sure that it is all clean.

To clarify a bit more the real issue seems to be the move from init.d to systemd and the configurations that are left in rc when this happens.

I found vestiges of three virtualbox packages, purged them and resinstalled guest additions, as suggested. This seems to have made the worrying syslog messages go away. Unfortunately I still cannot unmount shared folders! Oh well.

Giving up for now. Thanks for all your help.

UPDATE: according to this Debian bug report
https://bugs.debian.org/cgi-bin/bugrepo ... bug=799668,
the underlying issue is an incompatibility between vboxsf and Jessie's mount package. The workaround is to use .

Can you try out these steps??

This worked for me to unmount


> mount -t vboxsf SHARED_FOLDER_NAME /media/sf_seb


after you are done working with the sharing folder (available in the /media/sf_seb)

unmounting can be performed this way

>umount -t vboxsf SHARED_FOLDER_NAME

or

>umount /media/sf_seb



I hope it was not against the question that was raised.


tested in virtualbox 5.1.8 with windows 7 host and linux centos guest.

'umount -i' worked for me. host os is win7 guest os is archlinux. thanks @seberoon.