Complete Proxmox Backup Server Setup Guide: From Zero to Production-Ready Backups

For the best experience, ensure you have completed the “First Boot” guide.

Step 1: System Optimizations

Before starting, apply some system optimizations that are generally accepted as a good practice for PBS.

Reduce swap usage for better performance (PBS should use RAM):

echo “vm.swappiness=10” >> /etc/sysctl.conf

Disable IPv6 if your network doesn’t use it:

echo “net.ipv6.conf.all.disable_ipv6 = 1” >> /etc/sysctl.conf

echo “net.ipv6.conf.default.disable_ipv6 = 1” >> /etc/sysctl.conf

Apply settings immediately:

sysctl -p

Step 2: Storage Setup

Understanding Your Storage Options

PBS requires storage for two purposes:

1. Operating System and PBS software (~32GB minimum)

2. Backup datastore (where your actual backups are stored)

Option 1: Single Disk System

Using one SSD for both OS and backups.

Minimum Recommended Size: 256GB SSD (absolute minimum 128GB)

Pros:

• Simpler setup

• Less hardware required

• Lower cost

• Good for small deployments (5-10 VMs)

Cons:

• OS disk failure means losing backups too

• OS operations compete with backup I/O

• Can’t easily expand storage

• Harder to migrate to new hardware

Option 2: Dual Disk System

Separate disks for OS and backups (recommended).

Minimum Recommended Sizes:

• OS Disk: 64-128GB SSD

• Backup Disk: 500GB+ (depends on backup needs)

Pros:

• OS can be reinstalled without affecting backups

• Better performance (isolated I/O)

• Easy to add/upgrade backup disk

• Can move backup disk to new server

• Follows backup best practices

Cons:

• Requires additional hardware

• Slightly more complex setup

Single Disk Setups

For a single disk setup simply create a directory and add it as a datastore.

mkdir -p /mnt/datastore

Then add it as a datastore

proxmox-backup-manager datastore create main /mnt/datastore

Alternatively you could create a dedicated partition, however that adds some complexity without major advantages.

Dedicated Backup Disk

Identify Your Disks

Whether you are using a single disk or two, it is important to understand how your disks are setup. The best way is to list out the block devices on your host

lsblk -o NAME,SIZE,TYPE,FSTYPE,MOUNTPOINT,MODEL

In my case, I have a dedicated OS disk + a dedicated back up disk, and my output looks like:

NAME           SIZE TYPE FSTYPE      MOUNTPOINT MODEL
nvme1n1      476.9G disk                        TWSC TSC3AN512E6-F2T60S
├─nvme1n1p1   1007K part                        
├─nvme1n1p2      1G part vfat        /boot/efi  
└─nvme1n1p3  475.9G part LVM2_member            
  ├─pbs-swap     8G lvm  swap        [SWAP]     
  └─pbs-root 451.9G lvm  ext4        /          
nvme0n1        3.7T disk                        TEAM TM8FP4004T

From this I can see that my operating system is located on nvme1n1. There are a few indicators, first the /boot/efi mount point is on partition 2 (p2) of the nvme1n1. I can also see the lvm filesystem on partition 3 (p3).

The disk I will be using is the 3.7T nvme0n1.

File System

This guide will be using ext4

• Mature, stable, well-tested

• Good performance for PBS workloads

• Simple recovery if issues occur

• No additional RAM requirements

The first step will be to wipe the system

I have intentionally omitted the device to prevent accidentally copy and pasting my device. Make sure to fill in your device

wipefs -a /dev/<YOUR DEVICE>

Create a single partition using the entire disk

fdisk /dev/<YOUR DEVICE>

Then in fdisk:

1. Press ‘g’ - create new GPT partition table

2. Press ‘n’ - new partition

3. Press Enter to create partition 1

4. Press Enter for the default first sector

5. Press Enter for the default last sector (uses whole disk)

6. Press ‘w’ - write and exit

You can verify that the new partition was created with

lsblk | grep <YOUR DEVICE>

Format the partition (make sure to include the partition, like nvme0n1p1). I add the -m 0 to set reserved space to 0 as this is not needed

mkfs.ext4 -m 0 -T largefile -E lazy_itable_init=0,lazy_journal_init=0 /dev/<YOUR DEVICE><YOUR PARTITION>

• -m 0 = No reserved space

• -T largefile = Optimize for fewer, larger files (PBS chunks)

• -E lazy_itable_init=0 = Initialize now (better performance later)

Create the mount point

mkdir -p /mnt/datastore

mount /dev/<YOUR DEVICE><YOUR PARTITION> /mnt/datastore

Get the UUID of the disk

blkid -o value -s UUID /dev/<YOUR DEVICE><PARTITION>

Add permanent mount entry to fstab (replace UUID_HERE with output from above):

echo “UUID=UUID_HERE /mnt/datastore ext4 defaults,noatime 0 2” >> /etc/fstab

Test the mount configuration. First unmount the drive

umount /mnt/datastore

Then mount it via the fstab entry

mount -a

Verify

df -h /mnt/datastore

After mounting your storage, create the PBS datastore:

proxmox-backup-manager datastore create main /mnt/datastore

Step 3: Configure PBS

It is always a good idea to try and optimize when things run, here is the schedule I am following:

Optimized Job Schedule:

• 21:30 - Prune (frees space before backup)

• 22:00 - Backup (all nodes at once - your fast network can handle it)

• 01:00 - Verification (after backups complete)

• 02:00 - GC on Sundays only (weekly is sufficient)

Homelab-Optimized Retention:

• 3 most recent (quick recovery)

• 7 daily (one week)

• 4 weekly (one month)

• 2 monthly (two months)

• 0 yearly (unnecessary for homelab)

Configure Pruning

On PBS server - Set retention policy and schedule for automatic pruning:

proxmox-backup-manager prune-job create daily-prune \
    --store main \
    --schedule “21:30” \
    --keep-last 3 \
    --keep-daily 7 \
    --keep-weekly 4 \
    --keep-monthly 2

Homelab-optimized retention:

• --keep-last 3: Keep 3 most recent (for quick “oops” recovery)

• --keep-daily 7: Keep one per day for a week (most common recovery window)

• --keep-weekly 4: Keep weekly for a month (good balance)

• --keep-monthly 2: Two monthly backups (sufficient for homelab)

• --keep-yearly: This is omitted as we will do not yearly backups

• --prune-schedule “21:30”: Run 30 minutes before backups to free space

Configure Garbage Collection

On PBS server - Schedule garbage collection to reclaim space weekly:

proxmox-backup-manager datastore update main \
    --gc-schedule “sun 02:00”

Configure Verification

proxmox-backup-manager verify-job create verify-main \
    --store main \
    --schedule “01:00” \
    --ignore-verified true \
    --outdated-after 30

• verify-main: Job name

• --store main: Datastore to verify

• --schedule: Run daily at 01:00 (after backups complete)

• --ignore-verified: Skip recently verified backups

• --outdated-after 30: Re-verify backups older than 30 days

Create Backup User

On PBS server - Create a dedicated user for backup operations:

proxmox-backup-manager user create backup@pbs --password <YOUR PASSWORD>

On PBS server - Generate an API token that will be used later (copy this):

proxmox-backup-manager user generate-token backup@pbs api-token

On PBS server - Add the DatastoreBackup role to the user

proxmox-backup-manager acl update /datastore/main DatastoreBackup \
    --auth-id ‘backup@pbs’

On PBS server - Grant backup permissions to the API token (write-only for security):

proxmox-backup-manager acl update /datastore/main DatastoreBackup \
    --auth-id ‘backup@pbs!api-token’

Note: DatastoreBackup role allows creating backups but not deleting them - this protects against compromised nodes deleting existing backups.

Note: You MUST add the DatastoreBackup role to both the User and API token.

Step 4: Connect Proxmox VE

I am running a three node cluster and setting my backups at the datacenter level. Another option for this type of set up is creating a namespace for each node, and setting backups individually per-node. This is useful if you want to apply varying backup schedules depending on the VMs a node has.

On PBS server - Display the PBS certificate fingerprint needed for PVE (copy this):

proxmox-backup-manager cert info | grep Fingerprint

On ANY single PVE node (e.g., PVE0) - This command adds PBS storage for the entire cluster:

pvesm add pbs pbs-backup \
    --server 192.168.1.100 \
    --username ‘backup@pbs!api-token’ \
    --password ‘SECRET-TOKEN-STRING’ \
    --datastore main \
    --fingerprint ‘XX:XX:XX:XX:...’

You only run this ONCE on ONE node - it automatically becomes available on all cluster nodes!

Parameters explained:

• pbs-backup: Storage name in PVE (you can choose any name)

• --server: PBS server IP address

• --username: PBS user created earlier

• --datastore: PBS datastore name (we created “main”)

• --fingerprint: Certificate fingerprint from PBS

Datacenter-Level Backup (Recommended)

On ANY single PVE node - Create one backup job for all VMs on all nodes:

pvesh create /cluster/backup \
    -id datacenter-backup \
    -schedule “22:00” \
    -storage pbs-backup \
    -mode snapshot \
    -all 1 \
    -enabled 1

This single job will:

• Run every night at 22:00 (30 minutes after pruning at 21:30)

• Backup ALL VMs and containers on ALL nodes in the cluster

• Store everything in PBS’s main datastore

• Show up in every node’s web UI under Datacenter → Backup

Parameters explained:

• -id datacenter-backup: Job name (choose any name)

• -schedule “22:00”: When to run (optimized timing)

• -storage pbs-backup: PBS storage we added earlier

• -mode snapshot: Backup mode (no VM downtime)

• -all 1: Backup all VMs and containers on all nodes

• -enabled 1: Job is active

Note: The backup feature in Proxmox is extremely versatile. You can set backups at the datacenter level, node level, and even for specific VMs. Depending on the criticality of your VMs and network/hardware limitations, it may make more sense to only backup critical VM