hashicorp/vagrant · warning

Vagrant requires administrator access for pruning SMB shares

Error message

Vagrant requires administrator access for pruning SMB shares and
may request access to complete removal of stale shares.

What it means

On Windows hosts, Vagrant prunes stale SMB shares (shares whose Vagrant-managed ID no longer belongs to an active machine) by running an elevated PowerShell script. Before executing it, Vagrant prints this UAC warning, sleeps UAC_PROMPT_WAIT seconds, and then invokes the script with sudo: true, which may raise a consent dialog; a non-zero exit raises SyncedFolderSMB::Errors::PruneShareFailed.

Source

Thrown at plugins/hosts/windows/cap/smb.rb:57

        def self.smb_cleanup(env, machine, opts)
          script_path = File.expand_path("../../scripts/unset_share.ps1", __FILE__)

          m_id = machine_id(machine)
          prune_shares = existing_shares.map do |share_name, share_info|
            if share_info["Description"].to_s.start_with?("vgt-#{m_id}-")
              @@logger.info("removing smb share name=#{share_name} id=#{m_id}")
              share_name
            else
              @@logger.info("skipping smb share removal, not owned name=#{share_name}")
              @@logger.debug("smb share ID not present name=#{share_name} id=#{m_id} description=#{share_info["Description"]}")
              nil
            end
          end.compact

          @@logger.debug("shares to be removed: #{prune_shares}")

          if prune_shares.size > 0
            machine.env.ui.warn("\n" + I18n.t("vagrant_sf_smb.uac.prune_warning") + "\n")
            sleep UAC_PROMPT_WAIT
            @@logger.info("remove shares: #{prune_shares}")
            result = Vagrant::Util::PowerShell.execute(script_path, *prune_shares, sudo: true)
            if result.exit_code != 0
              failed_name = result.stdout.to_s.sub("share name: ", "")
              raise SyncedFolderSMB::Errors::PruneShareFailed,
                name: failed_name,
                stderr: result.stderr,
                stdout: result.stdout
            end
          end
        end

        def self.smb_prepare(env, machine, folders, opts)
          script_path = File.expand_path("../../scripts/set_share.ps1", __FILE__)

          shares = []
          current_shares = existing_shares

View on GitHub (pinned to 35f3160f4a)

Solutions

1. Run Vagrant from an elevated (Administrator) terminal so the elevated PowerShell call needs no interactive consent
2. Remove stale shares yourself in an elevated shell: `Remove-SmbShare -Name <share>` or via fsmgmt.msc
3. Use `vagrant destroy` to tear down machines so share pruning has little to do

Example fix

# before
vagrant up   # from a normal terminal, UAC dialog may appear mid-run
# after
# open an elevated PowerShell, then:
vagrant up

# PowerShell preflight: is this shell elevated?
([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)

When it happens

Trigger: Teardown or setup on a Windows host where prune_shares is non-empty — previously created Vagrant SMB shares whose machines no longer exist, e.g. after deleting .vagrant state or removing machines by hand.

Common situations: Leftover shares from manually deleted machines; running Vagrant from a non-elevated terminal so a UAC dialog interrupts the flow; CI agents without interactive elevation.

Related errors

• Vagrant requires administrator access to create SMB shares a
• Pruning an SMB share failed! Details about the failure are s
• The synced folder type '%{type}' is reporting as unusable fo
• Exporting an SMB share failed! Details about the failure are
• vagrant.commands.box.no_installed_boxes

AI-assisted analysis of hashicorp/vagrant@35f3160f4a (2026-08-21). Data as JSON: /api/errors/21ccdfff370b42b6. Report an issue: GitHub.