Reverse Sync Local And Remote Proxmox Backup Servers

by nprog October 19, 2021 · Blog / Proxmox

We can sync our local Proxmox backup server with an offsite second backup server, both backup servers can be VMs or they may be installed on a physical machine.

At first, the port forwarding is configured on our local network to receive inbound traffic from the Offsite Proxmox Backup Server. Facing problems with troubleshooting? Here is more to troubleshoot.

There are three major benefits of this backup strategy:

You can take backups while the VMs are running.
You will never lose backup, even in case of a local site disaster.
Software is free, Open Source, and always getting better.

Offsite Proxmox Backup Server Configuration

Next, we need to configure the remotes section in the Offsite Proxmox Backup Server, log in to the web interface, and from the left pane select Remotes—> select Add button then add the details for Local Backup Server:

The Remotes Section

Remote: Enter the name of the Local Backup Server.
Host: Enter the Public Static IP address of your Local Backup Server.
Auth ID: This will be root@pam.
Password: Enter the password for the root.
Fingerprint: At Local Backup Server, from Dashboard –>Show Fingerprint–> Copy the Fingerprint then paste it here.

Once the information is entered, select the Add button and then the Local Backup Server is added to your Offsite Backup Server.

Next, On the Offsite Backup Server, select Datastore —> Sync Jobs—>then select Add, and add the following details:

sync proxmox local and remote backup server, add a sync job.

The Sync Section

Local Data Store: Choose the Data Store from the list.
Local Owner: root@pam.
Sync Schedule: Choose a desired schedule from the list.
Rate Limit: Choose Accordingly.
Source Remote: If port forwarding is working correctly then this will show the Local Backup Server Data Store.
Remove Vanished: If checked, any snapshot removed from the Local Backup Server shall also be removed from the Offsite Backup Server so choose as desired.

Local Proxmox Backup Server Configuration

For better performance, It is advised to use a separate machine for the Local Proxmox Backup Server, also the Backup Server should reside on the same LAN segment as the Proxmox VE Server.

Next, add Local Backup as storage to Proxmox VE, select Server View –>Datacenter–>Storage–> Click Add–>and then Select Proxmox Backup Server, and add the following details:

ID: Type any name, once the configuration is complete, this will appear as the storage name.
Server: Type the Private IP Address of your Local Proxmox Backup Server.
Username: root@pam.
Password: The Local Proxmox Backup Server (PBS) password.
Datastore: The name for the Local PBS Datastore.
Nodes: If you are using a cluster then choose the desired nodes else let it be at default.
Fingerprint: Log in to Local PBS –> Click Dashboard–> from the right pane click Show Fingerprint–> then copy the Fingerprint and paste it here in the Fingerprint section –> then click Add.

If everything goes well then this will add Local PBS as storage. If you encounter any errors or issues, Here is more to troubleshoot.

VM Backup To Local Proxmox Backup Server

Keep the VM on, Select Server View–>Datacenter–>Backup–> Add, and then add the following details:

Node: Select your local Proxmox VE Server.
Storage: Select PBS Storage.
Schedule: Choose a desired backup schedule from the list. This may differ from or match your Sync schedule.
SelectionMode: Select, Include the selected VMS, and then select the checkbox against the desired VM from the list.
Send email to: Leave it blank for now, as you will need to configure SMTP, and POP settings, which is not in the scope of the article.
Compression: ZSTD, is by far the best compression type.
Mode: Snapshot, the first backup will be a full VM backup, and the rest of the backups shall be incremental backups containing only the changed bits (deltas/dirty bits).
Enable: Select the checkbox against Enable, otherwise, the job schedule will not execute.

After this click OK to create the backup job, this job will run at the Schedule time, furthermore, you can start the job immediately by selecting the Run now button.

create-a-vm-backup-job-on-proxmox-ve; sync local and remote proxmox backup server.

Sync Process Between The Two Backup Servers: Explained

As the backup job created on the Proxmox VE will execute according to the defined schedule, and new backups are created, the sync job defined on the Offsite Proxmox Backup Server will also sync its backup with the local Backup Server at its defined schedule, as the backups are synced in the reverse direction, this is also called reverse sync.

Here is an example of sync job history on the Offsite Proxmox Backup Server: