Per-Volume Options
Every RAM disk is stored on a tmpfs filesystem — the in-memory backend is the only one you need to think about. This page explains the per-volume settings you can tune from a disk’s detail view, beyond the basics covered in Creating your first RAM disk.
Which filesystem does a volume use?
All Persist disks use tmpfs — a filesystem whose contents live entirely in your Mac’s memory. There is no storage-backend choice to make: tmpfs is fast, uses only as much RAM as the data actually occupies (up to the size ceiling you set), and is the only backend the app ships.
That means the toggles below are the extent of what tunes a volume’s behavior. If a tool needs something unusual like a case-sensitive or Spotlight-indexed filesystem, a RAM disk isn’t the right backend for it.
What do the Advanced toggles do?
The Advanced section of a volume’s options holds sync and visibility settings:
- Hide from Finder sidebar (nobrowse) — on by default. The volume doesn’t appear on the Desktop or in Finder’s Locations; you reach it through its folder path like any directory. Turn it off if you want the disk to look and behave like a removable drive in Finder. Takes effect on the next mount.
- Disable FSEvents logging — stops the filesystem-event journal on the volume. Apps that watch folders for changes (build watchers, sync clients) rely on FSEvents; leave this off unless you know you want the disk invisible to such tooling. It can shave overhead on write-heavy scratch volumes.
- Preserve modification times on destination (sync option) — on by default; saved copies keep the files’ modification dates. Turning it off makes syncs marginally cheaper but confuses tools that compare timestamps (build systems, backup tools).
- Verify copies by checksum (sync option) — on by default; saves compare content rather than trusting size+date. Turning it off speeds up syncs of huge trees at the cost of weaker change detection — with timestamps also disabled, a same-size in-place edit can be missed by a save. Keep it on for data you care about.
Do the settings apply immediately?
They’re applied after every successful mount and whenever you change the options. These are best-effort niceties: if applying one fails, the mount still succeeds (the failure is logged, not thrown in your face).
Why did my volume’s name change when I renamed the folder?
A volume with no custom name displays its folder’s name. Give it a custom name in the volume settings if you want a stable label independent of the folder.
Where does the saved data actually go?
By default a volume’s saved contents are written into its backing folder on your SSD (see How it works). If you attach a remote storage provider, the save instead targets the remote — see Remote storage for how that changes the picture and how the app behaves when the network isn’t available.