Vagrant box cache persistence during vagrant up

Answer: No automatic update during vagrant up

Vagrant does not provide a configuration switch that forces a fresh download of a box when vagrant up is run. The only built‑in check is config.vm.box_check_update, which merely prints a warning if a newer version exists on the provider. To use the latest box you must manually run vagrant box update (or delete the cached file) before bringing the machine up.

How Vagrant treats identical checksums

When the provider serves a box that has the same SHA‑256 checksum as the cached copy, Vagrant considers the file unchanged and will not download it again. This means that if a provider replaces a box file with a different image that coincidentally has an identical checksum, Vagrant will continue to reuse the stale local copy. In practice, providers rarely generate identical checksums for altered content, but the behavior is defined by the checksum comparison logic.

Recommended workflow for keeping boxes fresh

1. vagrant box update – pulls the newest checksum and replaces the cached file if a newer version is available.
2. vagrant up – starts the machine using the updated box.

Alternatively, wrap the two commands in a small shell script or alias to streamline the process:

#!/usr/bin/env bash
vagrant box update
vagrant up

Because Vagrant’s cache is shared across all projects, updating a box once will benefit every Vagrantfile that references that box name.

Verification steps

• Run vagrant box list to see the cached boxes.
• Execute vagrant box update and watch for a "Updated" message.
• Use vagrant up --debug to confirm that the updated box is being used (look for the checksum in the debug log).