When an app is holding a folder open

If an app is still writing to a folder while it's being copied, the copy can end up half old and half new — and some apps' databases are damaged that way without any warning. So before a move, Storage Studio looks for apps that are using the folder and asks you to close them first.

What you see depends on where you start the move.

Moving from Storage Inspector

When you click Move to NVMe in Storage Inspector, Storage Studio checks which apps have files open in the folder before the confirmation sheet appears. If any do, the sheet shows a red box headed, for example, 2 apps currently using files in this folder, with each app listed.

1. Save your work in those apps.
2. Click Quit next to an app, or Quit all. Each app is asked to quit the normal way, just like pressing ⌘Q, so it can save and close properly.
3. After Quit all, Storage Studio waits a moment and checks again; after quitting a single app, click the check-again button beside Quit all. When nothing is left, it says All apps released the folder — safe to continue.
4. Click Move to NVMe.

You can also press Move to NVMe with apps still listed. That's allowed, but it may interrupt the app.

For a big folder, the check can run out of time. Then the sheet says We couldn't finish checking which apps are using this folder — that means "we don't know", not "nothing is". Quit anything that uses the folder, or use the check-again button.

The Move back to internal disk sheet has the same check and buttons — see Moving a folder back.

Folders that move only when their app is closed

Some folders in Storage Inspector belong to one particular app and are only safe to move while it's closed. Their button is Move when closed. If that app is running, a sheet opens titled, for example, Mail is still using this folder:

• Ask it to quit — the polite request. Storage Studio then checks that it really closed, showing Waiting for it to close….
• If the app stays open — usually because it's asking about unsaved changes — Storage Studio tells you so. Switch to the app, finish up, then click Check again.
• Only after a polite request has been refused does Force quit… appear. It ends the app immediately without saving, so it asks you to confirm first. Use it only for an app that has stopped responding.
• Continue becomes available once nothing is using the folder. It takes you to the normal move confirmation.

If Storage Studio isn't allowed to quit an app — because it belongs to another account or the system — it says so; quit it yourself, then click Check again.

%% caption: What happens when an app is using a folder you want to move
flowchart TD
  A[You start a move] --> B{Is any app using the folder?}
  B -->|No| F[Confirm the move]
  B -->|Yes| C[Ask the app to quit]
  C --> D{Did it close?}
  D -->|Yes| F
  D -->|No, it is asking about unsaved work| E[Switch to it, finish up, check again]
  E --> D
  B -->|Could not tell in time| G[Quit apps that use it, then check again]
  G --> B

In Data Parking: the recent-write guard

Data Parking protects you a different way. Before it copies a folder, it looks for any file inside that changed recently — by default within the last 12 h. If it finds one, that folder is held back and a message names it, starting Blocked 1 folder with recent writes. The other folders you ticked still move.

To change this, click the gear in Data Parking:

• Recent-write window — 1 h, 6 h, 12 h (the default), 24 h, 48 h or 72 h.
• Bypass recent-write guard — switches the check off. Leave it off unless you're deliberately moving work in progress, and close the apps using that folder first.

If a move still fails

If an app changes files during a copy, the move stops before your original is touched, and the Moves list explains it — for example that some files changed while they were being copied. Close the app and try again. See A folder move failed or was cancelled.

See also: Moving folders safely, How copies are checked, Files that change while they're being transferred.