Cleaning
Cleaning always goes select → preview → (dry run) → clean → results.
Preview
Preview… builds a plan: what will happen to each item and what will be skipped, and why.
The action for each item is:
| Action | When |
|---|---|
| Move to Trash | The default for everything. You can put items back. |
| Delete now | Only for regenerable caches, and only if you ticked Delete regenerable caches immediately. Frees the space right away. Also used for items already in the Trash when you confirm emptying it. |
| Run … | The rule has an official tool (brew cleanup, docker system prune…). OpenDisk runs it instead of deleting files. |
| Skip | Something is wrong: the app that owns it is running, it is protected, it is a symlink, it changed… The reason is shown. |
Dry run
Dry run performs every check of a real clean and reports what would happen, without changing anything.
Clean
Clean re-checks each item right before acting on it. An item is skipped if, since the preview:
- it changed (different folder, or modified),
- it became a symlink, or a folder above it did,
- the app that owns it was opened,
- it is no longer covered by its rule.
Results
The results screen shows the space really freed, measured on the disk before and after, not the sum of the sizes you selected.
That number can differ from what you selected:
- Moved to the Trash frees nothing until you empty the Trash. OpenDisk tells you how much went there.
- APFS clones and hardlinks share blocks with other files, so deleting one copy frees less.
- Local snapshots can keep deleted blocks for a while. See APFS snapshots.
- Other apps write to the disk at the same time.
Undo
Everything moved to the Trash is written to a journal (~/Library/Application Support/OpenDisk/journal.jsonl). Undo on the results screen puts the items back where they were, as long as nothing else took their place. From the command line: opendisk undo <run id>. Finder's Put Back works too.
Items that were deleted directly, or cleaned by an official tool, cannot be undone; that is why those are limited to caches the tools rebuild on their own.