Persist — Help Center
Answers to the questions users actually ask, with special attention to the behaviors that are easy to misunderstand: where your data really lives, what "Save to Disk" does and does not protect you from, and what happens when things go wrong.
Start here
If you read only one page, read How Persist actually stores your data. Almost every surprising behavior in the app follows from the model explained there.
Contents
| Page | What it covers |
|---|---|
| Getting started | First launch, the background helper approval, menu-bar vs. dock mode, trial and licensing |
| Creating your first RAMDisk | Choosing a folder, setting a size ceiling, and why “Persist changes on unmount” matters |
| How it works | The three copies of your data, why your folder "disappears" while mounted, which files are never synced |
| Data safety | Save to Disk, periodic sync, crashes and power loss, failed saves, recovering files by hand |
| Mounting & ejecting | Mount at launch, apps blocking eject, Finder eject behavior, quitting with mounted disks |
| Filesystems & options | tmpfs vs. APFS vs. HFS+, case sensitivity, Spotlight, the per-volume toggles |
| Memory & sizing | How much RAM a disk really uses, size limits, resizing, the memory gauge |
| Troubleshooting | Full Disk Access, reserved locations, helper problems, common error messages |
The three rules worth memorizing
- While a RAMDisk is mounted, everything you see at its path lives in RAM. The folder on your SSD underneath is hidden and unchanged until a save runs.
- While a RAMDisk is unmounted, the folder on disk is the source of truth. Anything you add, change, or delete there — deletions included — is what the next mount starts from.
- A save happens at unmount (and via periodic snapshots), not continuously. If the machine loses power while a disk is mounted, the work since the last save exists nowhere on disk — with one important partial exception covered in Data safety.