I'm trying to use a Vagrant box from someone else, and it works fine when I first start it, but after I stop it and restart it with either vagrant halt and vagrant up, or vagrant reload, I get the following error message:
Failed to mount folders in Linux guest. This is usually because
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
The error output from the last command was:
/sbin/mount.vboxsf: mounting failed with the error: No such device
Right now, searching for this error message turns up a lot of people having trouble with a bug Virtual Box 4.3.10, but that's not the problem I'm having.
It turns out, upgrading the Linux kernel will cause the Virtual Box Guest Additions to stop working until they are rebuilt by running the following command in the VM
sudo /etc/init.d/vboxadd setup
I had upgraded the kernel without thinking about it when I ran yum update (similar to apt-get upgrade) to get updates to other software.
Alternatively, if you install the dkms package as described here, then the kernel module should be automatically updated when the kernel is updated.