Skip to main content
Central’s main page, Stored Snapshots, lists every Edge, each of its instances, their jobs, and each job’s snapshots. The newest snapshot of each job is tagged latest.
Central snapshot list showing an Edge instance, decryption key controls, and Download and Delete buttons

An expanded Edge instance with a stored snapshot in a local demo deployment.

​
How snapshots are stored

Each snapshot is one encrypted tar.zst file in Central’s backup folder:
The fingerprint in the filename is the first eight characters of Edge’s path-and-size fingerprint. You can use it to restore a matching snapshot from Edge, but multiple snapshots can share it.

​
Download a snapshot

Click Download on a snapshot. Because snapshots are encrypted by Edge, Central’s UI asks for that Edge’s encryption key the first time: Browser decryption uses Web Crypto. Open Central over HTTPS, or through localhost for local use; a plain HTTP LAN address does not provide the secure browser context needed for decryption.
1

Copy the key from Edge

In Edge’s UI, find Encryption Key and click Copy. See Encryption key.
2

Paste it into Central

Paste it when Central prompts. Central checks it against the key fingerprint that Edge reported, so a wrong key is caught before decryption starts.
3

Save the file

The snapshot is decrypted in your browser as it downloads, and saved as a regular tar.zst archive.
The key is kept in that browser tab’s memory and session storage, never sent to Central’s server. Clear removes a saved key; signing out or returning to the sign-in dialog clears all saved keys in that tab, as does ending the tab session. To extract the downloaded archive:
To put files back on the original machine, restore from Edge instead. It downloads, decrypts, and extracts for you.

​
Delete a snapshot

Click Delete on a snapshot and confirm. This permanently removes the file.

​
Retention

After each upload, Central keeps the most recent Keep Last Snapshots (default 3) for that job and Edge instance, and deletes older ones. Edge instances never prune each other’s snapshots, even if they share an EDGE_ID. Ordering uses the stored files’ modification times. Preserve those times when copying archives back into Central’s backup folder. Change it in Edit Central Settings. See Design decisions.

​
Integrity checks

Central can re-check stored snapshots with SHA-256 to catch files that have been corrupted or changed on disk. Each check covers the latest snapshot of every job, not the full history, to stay lightweight.
  • Run Now: start a check from the integrity bar on the snapshots page.
  • Scheduled: set Snapshot Integrity Check Interval (hours) in Edit Central Settings. 0 turns scheduled checks off.
Central reads the check interval when it starts. After changing it, restart Central: docker compose restart central.
The bar shows the result of the most recent check and when it ran. Results are held in memory and reset when Central restarts. Snapshots without a recorded archive checksum are skipped. A successful check verifies the stored encrypted bytes, not whether you still have the correct decryption key.