from http://superuser.com/questions/640027/why-cant-i-chown-a-virtualbox-shared-directory

Notes:
- the method below might not work very well; try adding the mount -o remount command
to /etc/rc.local instead

I'm trying to recursively chown a VirtualBox shared folder, but I can't get it
to work:

$ ls -lah
total 16K
drwxr-xr-x  4 root root   4.0K Aug  1  2012 .
drwxr-xr-x 23 root root   4.0K Jul 21  2012 ..
drwxrwx---  1 root vboxsf 4.0K May  4 17:02 sf_dev
drwxrwx---  1 root vboxsf 4.0K Sep  2 10:21 sf_dropbox
$ sudo chown -R pknight:pknight sf_dropbox && ls -lah
total 16K
drwxr-xr-x  4 root root   4.0K Aug  1  2012 .
drwxr-xr-x 23 root root   4.0K Jul 21  2012 ..
drwxrwx---  1 root vboxsf 4.0K May  4 17:02 sf_dev
drwxrwx---  1 root vboxsf 4.0K Sep  2 10:21 sf_dropbox

I'm aware that I could just add a user to the vboxsf group (as it has full
permissions), but I don't want to give every user/daemon full permissions to
all of my shared folders.

I'm running VirtualBox 4.2.x, with Windows 7 as the host and both Xubuntu and
Debian as guests.

Is there any way for me to change the owner/group of my VirtualBox shared
directory?


-----


The VirtualBox shared file system (vboxsf) doesn't support POSIX permissions per se; rather, they are "set" at mount time:

$ mount
...
dropbox on /media/sf_dropbox type vboxsf (gid=1001,rw)

The gid bit specifies the group that owns the directory; on my system, this
happens to correspond with the vboxsf group.

You can alter the user and/or group ownership by remounting (must be done as
root):

# mount -t vboxsf -o remount,gid=1000,uid=1000,rw dropbox /media/sf_dropbox

Replace 1000 with the desired user/group IDs, and dropbox with the name of the
share (the part after sf_).

Note that this must be done after every reboot unless you edit /etc/fstab.