sudo mount -t vboxsf -o rw,uid=1000,gid=1000 shared ~/host

VBoxManage setextradata VM_NAME VBoxInternal2/SharedFoldersEnableSymlinksCreate/SHARE_NAME 1

$ touch test
$ ln -s test test2
$ ls -all test2
lrwxrwxrwx 1 $USER $USER 4 Spa 23 12:43 test2 -> test
$ rm test2
$ ln test test2
ln: failed to create hard link 'test2' => 'test': Operation not permitted

drwxr-xr-x  1 kristupas kristupas 4096 Spa 23 12:40 host