Using Vagrant NFS Synced Folders for Faster File Sync

Enable NFS synced folders in Vagrant

To get near‑native file performance in a Vagrant box, enable NFS synced folders. This bypasses the slower VirtualBox shared‑folder implementation by using the host’s NFS daemon and the guest’s NFS client, keeping data in the kernel page cache.

Worked Vagrantfile example

Vagrant.configure("2") do |config|
  config.vm.box = "ubuntu/focal64"
  config.vm.network "private_network", type: "dhcp"
  # Enable NFS synced folder for the project root
  config.vm.synced_folder ".", "/vagrant",
    type: "nfs",
    mount_options: ["nolock,vers=3,udp", "dmode=775,fmode=664"]
end

How it works

When vagrant up runs, Vagrant:

1. Starts the host’s NFS daemon (if not already running) and exports the host directory matching the first argument of synced_folder.
2. Boots the guest VM and installs the nfs-common package (you must ensure it is present; on Ubuntu/Debian run sudo apt-get install -y nfs-common as part of a provisioning script).
3. Mounts the exported directory inside the guest at the second argument (/vagrant) using the supplied mount options.

Because the NFS traffic stays on the private network interface and uses UDP by default, latency is low and throughput approaches that of a native file system.

Limitations and common mistakes

• Host must run an NFS server. On macOS enable Remote Login or start nfsd manually; on Linux ensure nfs-kernel-server is active. Windows hosts need the vagrant-winnfsd plugin or WSL2.
• Firewall/port 2049. The guest must be able to reach the host’s IP on TCP/UDP port 2049. If you see mount.nfs: Connection timed out, check the host’s firewall and that the NFS service is listening.
• UID/GID mismatches. Files may appear owned by the wrong user. Fix by adding uid and gid options or using dmode/fmode as shown.
• Changing guest IP. NFS exports are tied to a specific host‑guest IP pair. If the guest gets a new DHCP address after a suspend/resume, the mount can go stale. Use a static private‑network IP or reload with vagrant reload after IP changes.
• Performance on Windows hosts. Without the plugin, Windows cannot act as an NFS server, so the fallback is the slower VirtualBox shared folder.

To verify that NFS is active, log into the guest with vagrant ssh and run:

mount | grep /vagrant

You should see a line containing type nfs and the options you specified. Then create a test file on the host and check its presence and timestamps inside the guest to confirm synchronization.