vagrant で mount エラー

vagrant で centos6 を立ち上げて、yum update 後に、halt → up するとmountエラーがでた。

[default] Mounting shared folders...
[default] -- /vagrant
Failed to mount folders in Linux guest. This is usually beacuse the "vboxsf" file system is not available. Please verify that the guest additions are properly installed in the guest and can work properly. The command attempted was:

mount -t vboxsf -o uid=`id -u vagrant`,gid=`getent group vagrant | cut -d: -f3` /vagrant /vagrant
mount -t vboxsf -o uid=`id -u vagrant`,gid=`id -g vagrant` /vagrant /vagrant

対応方法は vbox の再構築らしい

$ vagrant ssh
$ sudo /etc/init.d/vboxadd setup

これで、halt → up して問題はなくなった