Getting Started
What does Persist actually do?
It creates disks whose contents live entirely in your Mac's memory (RAM). Reads and writes to a RAMDisk are far faster than to an SSD, and they cause no SSD wear — useful for build caches, scratch folders, browser profiles, audio/video intermediates, or any workload that hammers temporary files.
The trade-off is that RAM is volatile: its contents vanish when the disk is ejected, the app quits, or the Mac restarts or loses power. Most of this Help Center is about how the app bridges that gap — and where the bridge has limits.
Why does macOS ask me to approve a background item on first launch?
Mounting and unmounting filesystems requires root privileges. The app
installs a small privileged helper (a launchd daemon) that does exactly two
things: mount and unmount. Everything else — syncing, the UI, settings — runs
as your normal user.
macOS requires you to approve that helper under System Settings › General › Login Items & Extensions (allow it to run in the background). Until you do, the app cannot create or mount any disk, and it will show an alert asking you to approve the helper. If you accidentally declined, open that Settings pane and enable the Persist helper — no reinstall needed.
Why is the app asking for Full Disk Access?
Only if you place a RAMDisk's folder inside a location macOS protects
(Desktop, Documents, Downloads, and similar). The privileged helper mounts on
your behalf, so it needs Full Disk Access to touch those folders. The alert
includes a button that opens the right System Settings pane. If your mount
folders live in unprotected locations (e.g. directly under your home folder
or /Volumes), you will never see this prompt.
Note that Full Disk Access does not help with ~/Library/Containers and
~/Library/Group Containers — those are reserved by macOS at a deeper level
and can never be used as mount points. See
Troubleshooting.
What is the difference between menu-bar mode and dock mode?
- Dock mode: the app behaves like a regular app — dock icon, menu bar, and closing the main window quits the app (which triggers the save flow if disks are mounted).
- Menu-bar mode: the app lives as a menu-bar icon with no dock icon. Closing the main window leaves the app (and your mounted disks) running. The menu-bar panel shows each disk's state, last-sync time, and quick mount/eject actions.
If you rely on RAMDisks being available all day, menu-bar mode plus Open at Login is the intended setup: the app starts at login without opening a window, and every volume with Mount at launch enabled is mounted automatically.
Do my RAMDisks come back after a reboot?
The disks' contents do not survive a reboot by themselves — RAM is cleared. What comes back is whatever was saved to the backing folder on disk (see How it works). With Open at Login enabled for the app and Mount at launch enabled on a volume, the volume is remounted at login and refilled from its folder automatically. With default settings (Save to Disk on unmount enabled), a clean shutdown ejects your disks through the save flow first, so a normal reboot round-trips your data. A power cut or kernel panic does not run any save — see Data safety for exactly what survives that.
How does the trial work? What are its limits?
The trial runs for 10 days from first launch and allows up to 3 RAMDisks. When it expires, the app blocks disk management until a license is activated (your data is untouched — the backing folders and saved content stay on disk; the app just stops mounting until licensed).
One detail worth knowing: the trial clock is stored securely and is robust against setting the system clock backwards — rolling back the date does not extend the trial.
How do updates work?
The app updates itself via the standard Sparkle mechanism (the same "A new version is available" flow used by many Mac apps). You can check for updates from within the app; updates never touch your volumes' backing folders or saved snapshots.
Where does the app keep its own data?
- Volume definitions (not contents):
~/Library/Application Support/RAMDiskManager/registry.json - Saved snapshots used by the sync machinery:
~/Library/Application Support/RAMDiskManager/sync/ - Quarantined data rescued from failed deletions:
~/Library/Application Support/RAMDiskManager/recovered/
You should not edit these by hand while the app is running, but knowing the snapshot and recovered locations matters for manual data recovery — see Data safety.
Ready to make one? Continue to Creating your first RAMDisk.