USB vs SATA: The Unexpected Debate Behind Virtualized PBS Storage

Moving into a smaller space doesn't sound like the kind of life event that should force you to rethink your backup strategy, but here we are. When one home server enthusiast boxed up his setup—Proxmox on one machine, Proxmox Backup Server (PBS) on another, Pi-hole on a Raspberry Pi, and a whole spread of cables he no longer had room for—he found himself staring at a single PC and a simple question: How do you keep your backups safe when the luxury of multiple machines disappears? He had been running PBS bare metal for months without a hitch. Separate systems, separate responsibilities, and a clean mental model: hypervisor on one side, backups isolated on the other, and a firewall appliance humming along nearby. But once the moving truck left, reality kicked in. The new place didn't have space—physically or electrically—for all of it. The minimalist lifestyle tends to hit hardest not in the bedroom or kitchen, but in the homelab. So he virtualized. First PBS. Then OPNSense. Pi-hole was next on the chopping block. Suddenly, one box was expected to carry the weight of an entire home's digital life. And that brought him to the new, nagging problem: where to store PBS data when PBS itself was now a VM? In theory, the hypervisor should never store its own lifeboat, but homelabs aren't theory. They're a mix of constraints, duct tape, spare drives from old builds, and a philosophy that everything should keep running even when life gets weird. And nothing gets weirder than having to pick between a spare 4TB SATA drive and a USB hard drive as your lifeline. This is where things got interesting. The debate that unfolded wasn't a simple "USB bad, SATA good" argument. Instead, it revealed a whole ecosystem of opinions, habits, fears, hacks, and personal backup philosophies. A debate that started with storage choices ended up poking at something bigger: what "reliable" really means when your server is now a machine you can fit on a bookshelf. Let's break down how this conversation turned into a surprisingly rich look at running PBS inside a VM—and why the simplest choice isn't always the obvious one. ## The First Shot Fired: "USB absolutely NOT…" The first strong opinion landed fast. One commenter shut the door on USB with the kind of certainty usually reserved for network cables and religion. **USB absolutely NOT for sake of reliability.** Their recommended blueprint was clean: - Add extra NVMe or SATA storage directly to the Proxmox host. - Pass that drive straight through to the PBS VM. - Format it, mount it, and use it as a datastore. If the host ever dies, no problem—just pull the drive, drop it into a fresh PBS install, and all your backups pop back into existence like nothing happened. Passing through a physical disk is one of those homelab power moves: simple, elegant, and brutally effective. And for this user, USB wasn't even worth a footnote. It was the kind of swift judgment call that comes from years of seeing external drives randomly vanish mid-transfer. But the next reply pointed out something important: context matters. ## The Counterpunch: "USB isn't the villain here." Another seasoned voice jumped in, politely—but firmly—pushing back. Sure, USB can flake out. Sure, nobody wants a big ZFS pool hanging off a USB cable like a Christmas ornament. But a single USB hard drive used purely for PBS backups? That's not the end of the world. In fact, it comes with a very real benefit: you can unplug it. Unplugging a backup medium is old-school wisdom that never stopped being relevant. A powered-off, disconnected drive might not feel fancy, but it's resilient in ways fancy solutions aren't. If the server fries, gets hit by a surge, or takes a fall during a cleaning mishap, that unplugged USB drive doesn't care. It's not even awake. And there's a charm in that—cold storage is still one of the most reliable backup strategies ever invented. This user even name-dropped the beloved "3-2-1 rule," the classic mantra: - 3 copies of your data - 2 different media types - 1 stored offsite A USB drive isn't glamorous, but it fits neatly into that philosophy. The debate was no longer about ports—it was about the purpose behind the backup. ## The Practical Turn: "I have a spare 4TB SATA anyway…" Our original poster looked at both sides, weighed the advice, and realized something refreshingly human: he already had a 4TB SATA drive sitting around doing nothing. And that's the real homelab moment. You can read all the opinions you want, but the best solution is always the one that uses hardware you already own. So he went with the SATA passthrough. One commenter cheerfully confirmed it: **Correct. Format as EXT4, mount it, and go.** Just like that, the storage problem went from a philosophical argument to a solved puzzle. But the discussion didn't stop. Because once homelab people get going, they don't stop at answering the actual question. ## The Alternatives: NAS, NFS, and the Offsite Dream People jumped in sharing their own setups—not as "you must do this," but more like war stories. - Some ran PBS datastores on an NFS share from a NAS. - Others backed everything up to S3-compatible object storage. - One user was running PBS from a USB drive and syncing it nightly to another PBS instance. Cloud storage options like Backblaze B2, OneDrive (temporarily), and iDrive E2 got tossed into the mix. For someone on a tight budget after moving, these weren't immediate options—but they became part of the long-term wishlist. Another user recommended a clever two-tier system: - SATA drive passed through to PBS as the main datastore - a USB drive also passed through to PBS for mirrored backups - Daily sync job. Backups of backups. The whole thing automated. The homelab equivalent of sleeping with the door double-locked. This wasn't just a debate anymore—it was a buffet of strategies, each tailored to someone's quirks, fears, and budget. ## The Curveball: "Pass-through is not real virtualization." Just when it seemed like SATA passthrough had won the day, another voice arrived with a different take. To them, passing through a physical disk wasn't really virtualization. It was a compromise that might work, but it also tethered PBS too tightly to the host. If the goal is flexibility, attaching PBS storage as a virtual disk (qcow2 on USB or otherwise) kept things portable. Their logic: - No need to reinstall PBS if the host dies - No need to rebuild the datastore - Just move the drive, attach storage, boot up PBS VM, and keep going This is a very different way of thinking. It treats the entire PBS VM—storage included—like a movable appliance. And while it's not the majority approach, it's a valid one if modularity is your highest priority. A fringe opinion? Maybe. But it highlights just how many angles people bring into what seems like a simple question. ## The Bigger Story: Running Proxmox and PBS on One Machine More than a few people chimed in to say that running PBS and PVE on the same box is fine. Some consider it a red flag. Others call it overblown. One person bluntly put it: **I don't have unlimited space or money.** And that's really the heartbeat of the whole conversation. When you're running a homelab—not a corporate datacenter—your choices are shaped by: - the gear you already own - the space you can dedicate - the power you can afford - your tolerance for risk - and whether you're okay with things being good enough instead of perfect Our protagonist didn't choose to virtualize PBS because it was elegant or technically pure. He did it because he physically had nowhere to put another machine. And that's a story countless homelabbers can relate to. ## So… USB or SATA? Here's the real answer. After watching this debate play out across dozens of voices, one thing becomes clear: **Neither USB nor SATA is "right" universally. They're right depending on the goal.** ### If your top priority is reliability during daily operation: SATA passthrough wins. It's stable, fast, and clean. ### If your top priority is having a cold, unplugged, disaster-proof copy: USB wins. You can remove it, store it, or 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. This community conversation wasn't a fight. It was a shared notebook of lived experience. And buried in that is the real lesson: There is no single best way to run PBS as a VM. There's only the best way for your specific home, hardware, habits, and tolerance for chaos. ## The End State: A 4TB Drive, a Virtualized PBS, and a Peaceful Mind In the end, the original poster did exactly what many of us would do. He used the hardware he already had, followed the clearest advice, and built something that fit the life he's living now. - A 4TB drive passed through directly to PBS - EXT4 formatting - Virtualized backups running safely inside the same machine as PVE - Plans for cloud replication when the budget allows It's not flashy. It's not what a big corporate IT department would do. But it's real, practical, and sustainable. And honestly, that's the best kind of homelab story. Not perfection—just progress that fits real life.