USB vs SATA: The Unexpected Debate Behind Virtualized PBS Storage

Downsizing shouldn't force you to rethink your backup strategy, but here we are. One homelabber boxed up his setup—Proxmox on one machine, Proxmox Backup Server (PBS) on another, Pi-hole on a Raspberry Pi—and ended up with one PC and no room, physically or electrically, for the rest.

PBS had run bare metal for months, a clean mental model: hypervisor on one side, backups isolated on the other. Now PBS was a VM, with OPNSense virtualized too and Pi-hole next. Which raised the question: where does PBS data live when PBS itself is a guest?

In theory, the hypervisor should never store its own lifeboat, but homelabs aren't theory.

Homelabs run on spare parts, which is how a 4TB SATA drive ended up in a knife fight with a USB hard drive.

The First Shot Fired: "USB absolutely NOT…"

The first opinion landed with the certainty usually reserved for network cables and religion.

USB absolutely NOT for sake of reliability.

The blueprint:

• Add extra NVMe or SATA storage directly to the Proxmox host.
• Pass that drive straight through to the PBS VM.
• Format it, mount it, use it as a datastore.

If the host dies, pull the drive, drop it into a fresh PBS install, and the backups reappear.

The Counterpunch: "USB isn't the villain here."

Another voice pushed back. Nobody wants a big ZFS pool hanging off a USB cable like a Christmas ornament, but one USB drive purely for PBS backups has a real benefit: you can unplug it.

If the server fries or takes a surge, an unplugged drive doesn't care. Cold storage is still the most reliable trick there is, and it fits the beloved "3-2-1 rule":

• 3 copies of your data
• 2 different media types
• 1 stored offsite

The Practical Turn: "I have a spare 4TB SATA anyway…"

Our poster landed somewhere refreshingly human: he already had a spare 4TB SATA drive doing nothing.

So he went with SATA pass-through. A commenter confirmed:

Correct. Format as EXT4, mount it, and go.

The Alternatives: NAS, NFS, and the Offsite Dream

Others shared their setups.

• Some ran PBS datastores on an NFS share from a NAS.
• Others backed up to S3-compatible object storage.
• One ran PBS from a USB drive, syncing nightly to a second PBS instance.

Backblaze B2, OneDrive (temporarily), and iDrive E2 went in too—wishlist items on a post-move budget.

Another suggestion, two-tier:

• SATA drive passed through to PBS as the main datastore
• a USB drive also passed through for mirrored backups
• daily sync job, fully automated

The homelab equivalent of double-locking the door.

The Curveball: "Pass-through is not real virtualization."

Then a dissent: passing through a physical disk isn't really virtualization, and it tethers PBS to the host. A virtual disk (qcow2 on USB or otherwise) stays portable.

• No need to reinstall PBS if the host dies
• No need to rebuild the datastore
• Move the drive, attach storage, boot the PBS VM

Fringe, but valid if you value modularity.

The Bigger Story: Running Proxmox and PBS on One Machine

Plenty said running PBS and PVE on one box is fine; some call it a red flag, others call that overblown. One person put it bluntly:

I don't have unlimited space or money.

In a homelab, choices are shaped by:

• the gear you already own
• the space you can dedicate
• the power you can afford
• your tolerance for risk
• whether good enough beats perfect

He didn't virtualize PBS for elegance. He had nowhere else to put it.

So… USB or SATA? Here's the real answer.

Neither USB nor SATA is "right" universally. They're right depending on the goal.

If your top priority is reliability during daily operation:

SATA pass-through wins. Stable, fast, clean.

If your top priority is having a cold, unplugged, disaster-proof copy:

USB wins. Remove it, store it, take it offsite.

If your top priority is portability and modular rebuilds:

Virtual disks win.

If budget is tight:

Use whatever spare drive you already own.

If you care about the "3-2-1 rule":

Mix and match. Local SATA + USB copy + cloud replication via rclone.

There is no single best way to run PBS as a VM. Only the best way for your home, hardware, habits, and tolerance for chaos.

The End State: A 4TB Drive, a Virtualized PBS, and a Peaceful Mind

He used the hardware he had and built something that fits the life he's living now.

• A 4TB drive passed through directly to PBS
• EXT4 formatting
• Virtualized backups running inside the same machine as PVE
• Plans for cloud replication when the budget allows

Not flashy, not what a corporate IT department would do. But real, practical, sustainable.