SFTP
Configure an SFTP server as external storage for your backups.
Portabase can push backups to any server reachable over SFTP (SSH File Transfer Protocol). This is a good fit when you already have an SSH-accessible host (a NAS, a VPS, or a dedicated backup box) and want to keep backups on infrastructure you control.
Prerequisites
- An SFTP/SSH server reachable from the Dashboard and from your agents.
- A user account on that server with write access to the target directory.
- Either a password or an SSH private key for that account.
Configuration on the dashboard
In Storage > Channels, click + Add Storage Channel and choose SFTP.
Fill in the connection fields:
| Field | Required | Description |
|---|---|---|
| Channel Name | Yes | A label for this channel in the dashboard (e.g. SFTP Channel). |
| Host | Yes | Hostname or IP of the SFTP server (e.g. backup.example.com). |
| Port | No | SSH port. Defaults to 22. |
| Username | Yes | The SSH user (e.g. deploy). |
| Password | No | Account password. Provide a password or a private key (or both). |
| Private key (PEM) | No | The SSH private key in PEM/OpenSSH format, starting with -----BEGIN OPENSSH PRIVATE KEY-----. |
| Remote path | No | Optional prefix on the server. Backups are stored under backups/YYYY-MM-DD/ beneath it. |
| Max connections | No | Maximum simultaneous connections per backup job. Empty means unlimited. See Max connections. |
| Host key | No (recommended) | The server's public host key, so backups are never sent to a server impersonating it. See Host key. |
You must provide a password or a private key (or both). Key-based authentication is recommended.
Click Test Storage to verify the connection, then Add Channel to finalize.
Host key
Without a host key, Portabase connects to whatever server answers at that address. With one, the Dashboard and the agents only talk to the server holding that key, and refuse a server that impersonates it.
On a trusted machine, run:
ssh-keyscan -p 22 backup.example.comPaste the whole output into Host key. Comment lines are ignored, and a server with several keys (ed25519, ecdsa, rsa) can be pasted as is, up to 16 keys. Paste full public keys: fingerprints (SHA256:…) are refused.
If the server's key changes, for example after a reinstall, connections fail and backups stop until you paste the new key. Leave the field empty to connect without checking.
The host key and the connection limit require Agent 1.25.0+. Older agents ignore them: they connect without checking the key and without a limit.
Max connections
Some providers cap the number of simultaneous SFTP connections per account, such as a Hetzner Storage Box (10). Above the cap, the server drops connections and backups fail.
Max connections limits the connections that each backup job opens to the server, whatever the method (archive upload, Snapshots, Sync or Copy). Jobs that run at the same time each use their own connections: keep the number of jobs running together, multiplied by this value, under your server's limit. Leave it empty for no limit.
Verification
- Log into the web UI.
- Trigger a manual backup on an agent using this channel.
- Connect to the SFTP server and confirm the backup file exists under the remote path (
backups/YYYY-MM-DD/).
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