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.