I have a shared folder between Xubuntu 16.04 (host) and Xubuntu 17.10 (guest). I have given write permission via virtualbox, but still I don't have permissions to edit the files on the guest system.

That is, because the folder is mounted to the guest system by

sudo mount -t vboxsf folder share

In the host system the folder is owned by the normal user and writable. But when mounted in guest, its owned by root and not writable for others. And when I try to change it via sudo chmod or sudo chown there is no effect.

In another Question it was answered, that you should give chmod 777 to all files on the host system. But thats not something I want to do because I don't see why this should be necessary to do. Giving all permissions to all users on my host system cant be the best way.

I already added my guest user to the vboxsf group but that didn't change anything. I guess, I would need to mount the shared folder somehow not by root.

  • If the folder is owned by root in the host then you own user (at the host) cannot write to it either. How would the VM do it then?
    – user692175
    Nov 22, 2017 at 0:58
  • 1
    Ownership alone does not determine who can write to it. What are the group and permissions? Typically, the permissions are 775 and the group is vboxsf, to which you add any user who needs write access.
    – fkraiem
    Nov 22, 2017 at 1:29
  • @MichaelBay : on the host the files are owned by the normal user, not by root. Just when mounted on the guest system they are owned by root
    – Jeno
    Nov 22, 2017 at 1:31
  • And using guest additions won't help? Nov 22, 2017 at 5:53

1 Answer 1


The solution is easy, just mount the shared folder for the standard user:

sudo mount -t vboxsf folder share -o uid=1000,gid=1000

1000 is the default ID of the default user. This can be checked by id username

  • That only works if 1000 is the only use that needs write access, so it's not ideal.
    – fkraiem
    Nov 22, 2017 at 4:28
  • why? whats the problem? That way its still 775 and owned by the guest user. Ok, when I would need files that would need to be edited and read by other (system) users it would be more complicated, but thats not the case here.
    – Jeno
    Nov 22, 2017 at 9:44

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