Complete ZimaCube Backup Guide: A Three-Layer Strategy With PBS, Synology, and Cloud Backup

Backup is not a glamorous topic—until the moment your data is gone.

ZimaCube’s hardware configuration gives it a natural advantage as a backup hub: six drive bays for a storage pool, NVMe storage as a fast backup target, and dual 2.5GbE ports for data transfer. This guide walks you through building a three-layer backup chain: VMs → PBS → local storage → cloud.

This guide assumes that you are already running Proxmox VE on ZimaCube. If you are still using ZimaOS, the backup strategy will be different. You can use ZimaOS’s built-in snapshot and remote sync features instead.

Step 1: Install Proxmox Backup Server

Proxmox Backup Server, or PBS, is Proxmox’s official backup solution. It supports incremental backups, deduplication, compression, and encryption. It can run on the same ZimaCube as Proxmox VE, installed as a virtual machine.

1. Download the PBS ISO from proxmox.com.
2. Create a new VM in Proxmox VE:
   • ID: 300
   • Name: pbs
   • Disk: 64GB for the system disk
   • CPU: 2 cores
   • Memory: 4096MB
   • Network: bridged, with a static IP address
3. Mount the PBS ISO and start the installation.
4. The installation process is similar to Proxmox VE: select the target disk, set the IP address, and configure the root password.
5. After installation, visit the PBS web interface in your browser: https://PBS-IP-address:8007

Step 2: Configure Backup Storage

PBS needs storage space to store backup data. There are two options.

Option A: Passthrough a Large HDD or NVMe Drive

If you have a dedicated drive as the backup target:

Initialize the disk in PBS. This example assumes the disk is /dev/sdb.

Run this in the PBS Shell.

mkfs.ext4 /dev/sdb

mkdir /mnt/backup

mount /dev/sdb /mnt/backup

In the PBS web interface, go to Administration → Storage/Disks → Directory → Create. Set the path to /mnt/backup and name it backup-store.

Option B: Mount ZFS/NFS Storage From the Proxmox Host

Add a second virtual disk to the PBS VM and place it on ZimaCube’s large-capacity ZFS pool. For a home environment, this approach is simpler.

Step 3: Add PBS Storage in Proxmox VE

Return to the Proxmox VE web interface:

1. Go to Datacenter → Storage → Add → Proxmox Backup Server.
2. ID: pbs-backup
3. Server: the IP address of PBS
4. Username: root@pam
5. Password: the PBS root password
6. Datastore: select the backup-store you just created
7. Click Add

Step 4: Create a Backup Job

Go to Datacenter → Backup → Add.

Incremental backup is the core strength of PBS. Only the first backup is a full backup. After that, daily backups only transfer changed data blocks. For a typical setup with six VMs, daily incremental backups usually finish within 5–10 minutes.

Step 5: Notification Settings — Only Make Noise When Needed

A good backup system does not need you to check it every day. It only notifies you when something goes wrong.

In the PBS web interface, go to Configuration → Notifications:

• Add an SMTP configuration using your email account.
• Set notification rules: do not send notifications for successful backups, but notify immediately when a backup fails.

Apply the same setup in Proxmox VE as well: Datacenter → Notifications.

This way, you will mostly forget that the backup system exists—until one day you receive a “Backup failed” email. You can then fix the issue immediately before a small problem becomes a big one.

Step 6: Prune — Automatically Clean Up Old Backups

Backups accumulate over time. PBS’s Prune feature automatically removes expired backups.

Configure the Prune policy in the PBS Datastore settings:

• Keep daily backups from the last 7 days
• Keep weekly backups from the last 4 weeks
• Keep monthly backups from the last 3 months

When you delete a VM in Proxmox VE, PBS will automatically remove it from the backup schedule. It will not keep creating orphaned backup jobs that waste space. This small detail means you do not need to clean things up on both systems every time you delete a VM.

Step 7: Cloud Backup as the Final Safety Net

Local backups cannot protect you from fire or theft. You still need a cloud copy.

If you have a Synology system, whether virtualized or running separately, you can use Cloud Sync to sync the PBS backup directory to Google Cloud, Backblaze B2, or OneDrive:

VMs/CTs → PBS incremental deduplication → ZFS local storage → Cloud Sync → cloud storage

No Synology? Here are two alternatives:

• rclone: Install rclone in PBS and sync the backup directory directly to S3, Backblaze B2, or Google Drive.
• Duplicati: Run Duplicati in an LXC container, encrypt the backups, and upload them to any cloud storage provider.

The “Circular Backup” Myth

To be completely honest, this setup does have a theoretically imperfect loop:

PBS runs as a VM on ZimaCube → PBS writes backup data to ZimaCube’s ZFS pool → if the entire ZimaCube fails, all local backups fail at the same time

This is a real risk, and it is also a point that many people discuss.

But in practice, the protection chain works like this:

• If a ZimaCube drive fails, ZFS RAID-Z2 can tolerate up to two drive failures without data loss.
• If a single VM fails, PBS can restore it directly.
• If the entire ZimaCube fails, such as due to a power supply or motherboard issue, the cloud copy becomes the final fallback.

For a home lab, practical is more important than perfect. This setup runs automatically, alerts you when something goes wrong, and still gives you a cloud copy in the worst-case scenario. It is not perfect, but it works.

Verification: An Untested Backup Is Not a Backup

Spend 10 minutes each month running a recovery drill:

1. Create any test VM in Proxmox.
2. Use PBS to restore a real VM to a different VM ID.
3. Start the restored VM and confirm that its services run correctly.
4. Delete the test VM.

Those 10 minutes are your only defense against the possibility that “the backup has actually been broken for a long time, but I never knew.”

Summary

A good backup system is not something you “set and forget.” It is something you set up so that it knows when to remind you to pay attention.