Backing up Proxmox LXCs/VMs to TrueNAS Scale

One of the reasons I wanted to set up an actual NAS on my network was because I wasn't able to backup all my Proxmox containers the way I really wanted to. With the space I had allocated in Proxmox I was really only able to have one days worth of backups, with the exception of my "dev" container, which I was keeping about three days worth. My solution to this was to set up a TrueNAS instance and send all the Proxmox backups there.

These steps assume you already have Proxmox and TrueNAS set up and running on your local network

Datasets

I'm making this dataset at the top level of my pool. It will be the main folder for all the devices I save backups for, but right now I'm just setting it up for Proxmox.

Creation

Click the "Add Dataset" button at the top right of the screen
Give your dataset a name. I'm calling mine backup
Add a comment if you want: Top level backup dataset
Click "Save"

Once that's done, you should see the "backup" folder as a child of your main pool.

Click the "backup" dataset and add another dataset to that one. We're basically just making folders here. I'm calling this dataset proxmox-backup and the comment is just something like Used for Proxmox backups
Click "Save"

Once again, we see this new folder as a child, but this time it's a child of the "backup" folder

You can probably see where I'm going with this. Eventually I'll have other folders like phones, laptops etc... and each folder will have different permissions based on who/what is pushing data to them. And speaking of permissions...

Permissions

With the proxmox-backup dataset still selected, click the "Edit" button on the Permissions card
Select all the checkboxes*
Save

* I feel like the proper way to do this is by setting the permissions based on just the user or just the group, but I couldn't seem to get Proxmox to bring in the share like that. So to make up for that, in the next step we set it up so only the Proxmox IP address can access the share 🤷‍♀️

Sharing

Click the "Shares" button in the menu on the left
On the UNIX (NFS) Shares row, click the "Add" button
In the Path section, select the folder you just made for Proxmox backups
Add a description if you want. It doesn't really matter.
In the Hosts textfield, add the IP address of your Proxmox server 192.168.X.X. This will make it so only the Proxmox container can write to this dataset
Save

That's it for the TrueNAS part of it. Now we'll set up Proxmox.

Configuring Proxmox

In Proxmox, select your Datacenter and select the "Storage" tab
Click the "Add" dropdown and select "NFS"
Give it an ID. Mine will be truenas-backup
Enter the IP address of your TrueNAS server
Click the dropdown for the Export option and the path to the dataset we created in TrueNAS should be shown. Select that.

Since this is only going to be for backing up Proxmox, I'm going to deselect the default Disk Image option in Content and select VZDump backup file instead

Everything else can stay the same.

Click "Add"

Configure backups to use the TrueNAS dataset

Still on the Datacenter section

Select "Backup" from the menu
Click the "Add" button at the top
In the Storage dropdown, select the truenas-backup we just created

For the schedule I set it to 04:00 so it runs the backup at 4am every night

For Selection Mode I keep it on "Include selected VMs" and select the ones I want to backup

On the "Retention" tab I have it set to Keep Last: 3 and Keep Daily: 3 so it will always have the last three days of backups

Click the Create button

Test it out

When you select the new backup task that we just created, the "Run now" button should become enabled. Click that to start the backup.

Go to your TrueNAS Datasets page and select the proxmox-backup dataset and refresh the page. If everything worked correctly, the Total Allocation value should now reflect the size of your backups.

Now that it's finished I can see that it wrote 28GiB to the dataset, which means if I'm keeping three days worth of backups, the total size it occupies should be around 84Gib

pywkt