Virtualbox – Sharing Folders with the correct permissions

# Add current user to vboxsf group in Ubuntu guest OS
sudo usermod -aG vboxsf $USER

#You can access the share by making the user, or group id of 1000, a member of group vboxsf.
#This is done by changing the vboxsf line in the /etc/group file. May require reboot.
#File permission issues with shared folders under Virtual Box (Ubuntu Guest, Windows Host)

# add the following lines to .bashrc
mkdir -p ~/host/share
sudo mount -t vboxsf -o uid=1000,gid=1000 share ~/host/share

Stuff which I tried but did not work

Adding mount to fstab

The issue here is that vboxsf is not yet loaded when /etc/fstab is loaded.
I added vboxsf to /etc/modules but still had no luck.

Adding mount to rc.local

# So to add ownership and automatically mount in virtualbox via vboxsf in Ubuntu
# add to the /etc/rc.local file before the exit 0 line the command as follows:
# mount -t vboxsf -o uid=1000,gid=1000  /home//where/ever/you/want

# add shared folder to destination mount point in /etc/rc.local just before "exit 0"

if sudo grep -q "mount -t vboxsf -o uid=1000,gid=1000 share" /etc/rc.local; then
   echo "share mount already added"
else
   echo "adding share mount";
   # remove exit 0
   sudo sed -i "s/exit 0//g" /etc/rc.local
   # add new lines with exit 0
   sudo tee -a /etc/rc.local << EOF
mkdir -p ~/host/share
sudo mount -t vboxsf -o uid=1000,gid=1000 share ~/host/share
exit 0
EOF
fi

cronjob

sudo crontab -e
# add the following line
@reboot  mount -t vboxsf -o uid=1000,gid=1000 share /home/a/host/share

Troubleshooting

1. Appending the line vboxsf to /etc/modules did not work for me

Command Notes

a@a:~$ sudo mount -t vboxsf -o uid=$UID,gid=$GID sharea /home/a/sharea
gid= requires an argument (i.e. gid==)
a@a:~$ sudo mount -t vboxsf -o uid=$UID,gid=1000 sharea /home/a/sharea
/sbin/mount.vboxsf: mounting failed with the error: Protocol error
a@a:~$ sudo mount -t vboxsf -o uid=$UID,gid=1000 sharea /home/a/sharea
/sbin/mount.vboxsf: mounting failed with the error: Protocol error
# reason: using a different folder name than the share directory configured in the Virtualbox

a@a:~$ sudo mount -t vboxsf -o uid=$UID,gid=1000 vb-share-folder ~/host/share

#ln -s /media/sf_{mount_name} to /var/www/mountpint
#ln -s /media/sf_hosta to /home/a/host/a

References

1. http://mikefunk.com/2014/01/22/automounting-with-virtualbox/
2. http://askubuntu.com/questions/481559/how-to-automatically-mount-a-folder-and-change-ownership-from-root-in-virtualbox