XDA ran a piece this month about pairing Proxmox Backup Server with cheap S3 buckets for offsite backups, and it lit up home lab forums for a reason. LXCs and VMs die, drives fail, and a local Proxmox Backup Server on the same rack does not save you from a house fire. The best apps for Proxmox offsite S3 backup on desktop are the ones that plug into an existing PBS deployment or replace it entirely, then push encrypted, deduplicated snapshots to a bucket for less than a dinner out.
We tested eight tools against a Proxmox VE 8 cluster with a mix of LXCs, small VMs, and a large media dataset. Each was judged on encryption defaults, deduplication ratio, bandwidth handling on a slow uplink, and how bad the restore experience gets in the middle of a real incident.
What to look for in a Proxmox offsite backup app
- Client-side encryption. The bucket provider should never see plaintext.
- Deduplication. Chunk-level dedup keeps a 200 GB VM to 30 GB on the second backup.
- S3 or S3-compatible target. Native support for Backblaze B2, Wasabi, R2, or self-hosted MinIO.
- Bandwidth throttle. So the nightly job doesn’t kill your daytime uplink.
- Restore ergonomics. Restore a single file, not just the whole snapshot.
- Prune and retention policy. Automatic cleanup of old snapshots without a cron war.
Quick comparison
| App | Best for | Platforms | Free plan | Starting price | Rating |
|---|---|---|---|---|---|
| Proxmox Backup Server | The Proxmox-native path | Linux | Fully free | Subscription for support | 4.9 |
| Restic | Encrypted CLI with deduplication | Windows, macOS, Linux | Fully free | None | 4.9 |
| Rclone | Any-to-any bucket transfer | Windows, macOS, Linux | Fully free | None | 4.8 |
| Kopia | Cross-platform GUI backup | Windows, macOS, Linux | Fully free | None | 4.7 |
| Duplicati | GUI backup for less technical users | Windows, macOS, Linux | Fully free | None | 4.4 |
| Borg Backup | Deduplicated archives, CLI | Linux, macOS | Fully free | None | 4.7 |
| MinIO | Your own on-prem S3 target | Linux, Windows, macOS | Fully free community | Enterprise pricing | 4.6 |
| Backblaze B2 | The cheap S3 destination | Web + any client | Free tier | $6/TB/mo | 4.8 |
The apps
1. Proxmox Backup Server for offsite S3 — Best Proxmox-native path
Proxmox Backup Server now speaks the S3 API natively for datastore sync. Set up a local PBS on the same LAN as Proxmox VE, then configure a remote datastore that mirrors to Backblaze B2, Wasabi, or your own MinIO bucket. Deduplication and encryption happen on the PBS side; the bucket only sees encrypted chunks.
Where it falls short: You need a working PBS server first. Restore performance from a bucket depends on the provider’s egress latency.
Pricing:
- Free: Fully free, community supported.
- Paid: Enterprise subscription from about €470/year for support and enterprise repository.
Platforms: Debian-based Linux.
Download: proxmox.com/en/proxmox-backup-server
Bottom line: The pick if you’re already committed to the Proxmox ecosystem. S3 sync is a first-class feature now.
2. Restic for Proxmox offsite S3 — Best encrypted CLI with deduplication
Restic is the small, fast, encrypted CLI backup tool that treats an S3 bucket as a first-class target. Chunk-level deduplication is the default. Point it at /var/lib/vz/dump on the Proxmox host or at a mounted PBS export, and every snapshot ships to the bucket encrypted with AES-256.
Where it falls short: CLI only. Big prunes on huge repositories can be memory-hungry.
Pricing:
- Free: Fully free, BSD 2-clause.
- Paid: None.
Platforms: Windows, macOS, Linux, BSD.
Download: restic.net · github.com/restic/restic
Bottom line: The default for anyone comfortable in a terminal. Pair with a systemd timer and forget about it.
3. Rclone for Proxmox offsite S3 — Best any-to-any bucket transfer
Rclone is the swiss army knife for moving files between local paths, S3 buckets, WebDAV, and forty other backends. It’s the standard tool for copying PBS’s own local datastore to a bucket on a schedule. Encryption is optional via the crypt backend.
Where it falls short: Doesn’t dedupe by itself. Best paired with a backup tool that does.
Pricing:
- Free: Fully free, MIT.
- Paid: None.
Platforms: Windows, macOS, Linux, BSD.
Download: rclone.org · github.com/rclone/rclone
Bottom line: Use this as the transport when you want to mirror an existing PBS datastore to a cheaper bucket.
4. Kopia for Proxmox offsite S3 — Best cross-platform GUI backup
Kopia is the modern deduplicating backup tool with a real GUI and a CLI, both talking to the same repository format. It targets S3, B2, R2, WebDAV, and SFTP out of the box. Web UI shows repository stats and lets you restore individual files.
Where it falls short: Younger than Borg and Restic. Some edge cases on Windows still need attention.
Pricing:
- Free: Fully free, Apache 2.0.
- Paid: None.
Platforms: Windows, macOS, Linux.
Download: kopia.io · github.com/kopia/kopia
Bottom line: The pick when you want a GUI on top of the Restic-style workflow without giving up cross-platform reach.
5. Duplicati for Proxmox offsite S3 — Best GUI backup for less technical users
Duplicati is a browser-managed backup tool that hides the CLI entirely. Schedules, targets, and encryption are all point-and-click. It talks to every major S3-compatible service. Good pick when the person restoring might not be the person who set it up.
Where it falls short: Older releases had reliability issues on large repositories. The current 2.x line is much better; still worth testing restores before trusting it.
Pricing:
- Free: Fully free, LGPL.
- Paid: None.
Platforms: Windows, macOS, Linux.
Download: duplicati.com · github.com/duplicati/duplicati
Bottom line: The right pick when a family member or a colleague needs to restore, and a terminal is not an option.
6. Borg Backup for Proxmox offsite S3 — Best deduplicated archives from a CLI
Borg Backup predates most of this list and still holds up. Deduplication is aggressive, encryption is client-side, and repositories are extremely portable. Native S3 is not built in, but pair Borg with rclone’s serve restic proxy or Borgmatic’s S3 hooks and you’re there.
Where it falls short: No built-in S3. You add a layer to reach a bucket.
Pricing:
- Free: Fully free, BSD.
- Paid: None.
Platforms: Linux, macOS.
Download: borgbackup.org · github.com/borgbackup/borg
Bottom line: The pick when you already run Borg on the host and just need an S3 side channel.
7. MinIO for Proxmox offsite S3 — Best self-hosted S3 target
MinIO turns any Linux, Windows, or macOS box into an S3-compatible object store. Point it at a NAS or a small VPS and you have a bucket to back up to, without paying Backblaze or AWS. Erasure coding and encryption are built in.
Where it falls short: You’re now maintaining the destination. Erasure coding wants at least four drives to earn its keep.
Pricing:
- Free: Fully free community edition.
- Paid: Enterprise licenses for support and additional features.
Platforms: Linux, Windows, macOS, containers.
Download: min.io · github.com/minio/minio
Bottom line: Pick this when your offsite is a rented VPS or a friend’s home lab you swap capacity with.
8. Backblaze B2 for Proxmox offsite S3 — Best cheap S3 destination
Backblaze B2 is the cheapest well-known S3-compatible bucket. Storage runs at about a sixth of AWS S3 Standard, egress is free up to 3x the stored amount, and it works with every client on this list. Set a bucket, generate an application key, point Restic or Kopia at it, and the offsite story is done.
Where it falls short: Not the fastest for large parallel restores. Small monthly cost, not free.
Pricing:
- Free: 10 GB free tier.
- Paid: $6/TB/month storage; egress mostly free for backup workloads.
Platforms: Web dashboard; any S3-compatible client on any OS.
Download: backblaze.com/cloud-storage
Bottom line: The default cheap bucket for offsite Proxmox backups. Nothing else at this price point has the same track record.
How to pick the right one
If you’re already on Proxmox Backup Server: PBS S3 sync plus Backblaze B2 is the shortest path. No extra tool.
If you don’t run PBS and want the smallest tool that works: Restic to Backblaze B2.
If you want a GUI: Kopia for power users, Duplicati for less technical restores.
If you already run Borg on your Proxmox host: keep it, add Rclone to ship the repo to a bucket.
If you want the destination on your own hardware: MinIO on a NAS, then any client above.
If bandwidth or budget is tight: cheap bucket plus Restic with a chunk-size tune. Egress on B2 is generous enough that testing a restore doesn’t wreck the bill.
FAQ
What is the cheapest offsite backup target for Proxmox? Backblaze B2 at $6/TB/mo, or a spare drive plus MinIO at a friend’s house for free.
Can Proxmox Backup Server push directly to S3? Yes. Recent PBS releases speak S3 natively as a datastore sync target.
Do I need to encrypt Proxmox backups if the bucket is private? Yes. Client-side encryption means the provider (or a subpoena to the provider) never sees plaintext. Every tool on this list encrypts by default.
How often should offsite Proxmox backups run? Nightly for most home labs. Weekly for anything that changes rarely. Restic and Kopia deduplicate, so daily jobs stay cheap.
What’s the best backup tool for a homelab beginner? Duplicati if you want a GUI, Restic if you’re comfortable with a terminal and want the fewest surprises.
