For syncing all folders in both direction, insert this into your Vagrantfile:
config.vm.synced_folder "my-project1", "/home/vagrant/my-project1", type: "rsync", :rsync__exclude => ['my-project1/mini_project2/target,my-project1/mini_project2/target,my-project1/mini_project3/target']
All the target folders are excluded from syncing.
Syncing only happens on
vagrant up and on
To sync every change from you host to guest you have to use: