Restoring

Restore a snapshot

In Backup Snapshots, the app's or elsewhere, choose the snapshot, and Restore Snapshot:

1. Restore Into: the app the data goes into. The snapshot's own app, or another, such as a staging copy to try the backup on first.
2. What to restore, depending on the snapshot:
   • a command's backup is loaded by a Restore Command run in the app, which reads the backup on its input, such as psql -U $POSTGRES_USER $POSTGRES_DB. The data backup's own restore command is offered;
   • a volume's backup goes into a Volume the app mounts, at a Path inside it. The whole snapshot, or one of its directories.
3. How, for a volume, below.
4. Stop the app while restoring, so it does not write while its data is replaced.

The restore runs as a task: its logs are in the app's Tasks.

Replace or overwrite

A volume's backup is restored one of two ways:

• Replace: the directory as it is now is moved aside, and the snapshot is restored into an empty one. The app gets exactly what it had at backup time. The old directory is kept, named ….before-restore-…, to go back to; delete it once you are sure. Replace always stops the app.
• Overwrite: the snapshot's files are written over what is there. Files made since the backup stay, and nothing is kept aside.

Replace is the one to get an app back to a known state.

Try it before you need it

A backup is worth what its restore is. Restore one into a copy of the app from time to time, such as a clone in staging, and check the app works on it.