Zfs

Every homelab ends up with SSDs doing several different jobs at once: booting the hypervisor, holding VM disks, backing a ZFS special vdev or SLOG, maybe just serving as bulk fast storage for a database. Most buying advice treats this as one decision, “get an SSD, more capacity is better,” and stops there. That’s fine for a boot drive. It’s a real mistake for anything doing sustained writes, and it can quietly cost you data integrity on a ZFS log device. The differences between consumer and enterprise flash are specific and they map directly onto which job a drive should actually do. ...

Every Proxmox host ships with snapshots built in, and they’re so easy to take that it’s tempting to treat them as your backup strategy. Click “Snapshot” before a risky change, click “Rollback” if it goes wrong, done. That workflow is genuinely useful, and you should use it. It is also not a backup, and conflating the two is one of the more common ways homelab operators discover, at the worst possible moment, that they had less protection than they thought. ...

Every hoard past a certain size has duplicates in it, and not the kind you know about. It’s not usually the obvious “Copy of file (1).jpg” pattern. It’s the same movie sitting in three different folders because a download client, a manual import, and an old backup all landed a copy in a slightly different place. It’s a photo library synced from two phones that both uploaded the same shot. It’s a decade of “just copy it over to be safe” that never got cleaned up. None of this shows up until you actually go looking for it, and by then it can be a meaningful fraction of your total storage. ...

Every data hoarder eventually hits the same wall: the motherboard only has six SATA ports, and the build calls for twelve drives. The instinctive fix is a cheap RAID card off eBay, and that instinct is almost always wrong. The actual answer, in nearly every homelab storage build, is an HBA flashed to IT mode. Here’s what that means, why it matters, and how to do it without turning a $40 card into a paperweight. ...

Every data hoarder eventually runs into the same uncomfortable fact: a hard drive can report a read as fully successful while quietly handing back the wrong bits. No error, no SMART warning, no crash. The file opens fine. It’s just wrong. That’s bit rot, and RAID redundancy alone does nothing to catch it, because RAID is built to survive a drive failing outright, not a drive lying to you about data it’s still perfectly willing to serve. ...

Proxmox will let you install onto ZFS during setup with a few checkboxes and move on with your life, and that’s exactly how a lot of people end up with a storage layout they didn’t actually choose. ZFS is the best storage option built into Proxmox for most homelab setups, but it comes with tradeoffs that are easy to ignore during install and expensive to fix once you’ve got VMs and containers living on top of it. Here’s what the pool layout choices actually mean, what ZFS does to your RAM, and how to pick a shape you won’t be re-doing in six months. ...

Somewhere in every data hoarder’s history there’s a drive that seemed like a great deal, went into an array without a second thought, and then turned a routine rebuild into a multi-day nightmare or a dropped drive. Almost every time, the actual cause is the same three letters: SMR. This isn’t an obscure edge case. It’s happened at scale, publicly, more than once - manufacturers quietly shipping SMR drives in product lines everyone assumed were CMR, and the data hoarding and NAS communities finding out the hard way when arrays started misbehaving. If you’re buying drives for a NAS, a ZFS pool, or any kind of RAID array, this is one of the few things worth actually understanding before you buy, not after. ...

Updated Aug 12, 2026: added ZFS-vs-traditional-RAID comparison, a rebuild-risk worked example, and a monitoring checklist. “RAID is not a backup” gets repeated so often it’s lost meaning. Here’s the version that actually helps you pick a redundancy level instead of just feeling vaguely guilty about your array. What redundancy actually protects against Redundancy (RAID-Z1, RAID-Z2, mirrors, whatever flavor) protects against drive failure, full stop. It does not protect against: Accidental deletion (redundancy dutifully replicates your mistake) Ransomware or file corruption that writes bad data (same problem) Fire, theft, flooding, or anything that takes out the whole box at once Controller or power supply failure that kills multiple drives simultaneously That’s what backups are for, and it’s a separate problem from redundancy. This post is specifically about the “how many drives can I lose without losing data” question. If you only take one thing from this post, take the 3-2-1 rule for the data you actually care about: 3 copies, on 2 different types of media, with 1 copy off-site. Redundancy is not one of the three copies - it just keeps your primary copy available while a drive is being replaced. ...