Ceph vs ZFS vs NAS: The Truth About High Availability Storage in Proxmox

# Ceph vs ZFS vs NAS: The Truth About High Availability Storage in Proxmox Actually, if you've ever stared at a rack of servers and wondered whether you're doing your storage setup all wrong, you're not alone. High availability (HA) in Proxmox is a dream many chase - but how you achieve it depends heavily on which storage strategy you bet on: Ceph, ZFS, or traditional NAS. Each comes with its perks, pitfalls, and straight-up misconceptions. And based on some heated, insightful (and sometimes hilarious) user stories floating around online, it's clear that many teams are still figuring out which direction to go. So let's cut through the buzzwords and marketing fluff to break it all down: what actually works, what doesn't, and which of these options makes the most sense for your Proxmox setup. --- ## The Ceph Hype - And When It's Totally Worth It Ceph has become the unofficial king of distributed storage - especially in hyper-converged environments like Proxmox. When you do it right, it's fast, self-healing, and incredibly tough. The integration with Proxmox is seamless: you can spin up OSDs, monitor health, and manage pools directly from the GUI. For many, it "just works." But the moment you try to Frankenstein a Ceph setup using a single monster "storage node" and a few compute boxes with tiny SSDs? That's where everything starts falling apart. One user nailed it: Ceph isn't the problem - it's the way people set it up that causes chaos. If you're centralizing 80% of your storage on one node, you're building a SAN with extra steps, and Ceph isn't going to save you from yourself. Modern Ceph setups don't need a dozen nodes either. Several admins chimed in saying their three-node Ceph clusters ran great, with full redundancy, performance, and no weirdness - as long as they avoided mixing drive types, kept RAID controllers out of the picture, and maintained decent networking (think 25/40/100GbE, not your dusty office switch). **Pro tip**: For a smooth ride, use enterprise SSDs, avoid SMR drives like the plague, and make sure your HBAs are in IT mode. --- ## ZFS: The "Good Enough" Workhorse That Just Won't Quit ZFS isn't sexy. It doesn't have the marketing push of Ceph. But it's beloved for a reason: it works, and it works well. In smaller Proxmox deployments, ZFS with replication can get you surprisingly close to what most would consider "HA." Is it true high availability? Not exactly. You might have a few minutes of downtime during a node failure, but for a lot of environments, that's an acceptable tradeoff. The key advantage here is simplicity. ZFS replication is dead easy to set up, even across nodes. You can point a VM's dataset to replicate to two or three other boxes. If one dies, you just boot from the replica. It's not instant, but it's reliable. As one admin bluntly put it: "Lots of people greatly exaggerate their uptime requirements and overengineer their cluster design because of that. ZFS is just perfect for lots of cases." There's also the performance angle. ZFS does great with local disk IO, especially when paired with fast SSDs and plenty of RAM. It also gives you granular snapshotting, compression, and checksumming, all baked in. That said, ZFS doesn't scale the way Ceph does. Once you get beyond 4–5 nodes, replication management can start to get tedious, and real HA - with fencing and failover - becomes harder to maintain manually. --- ## NAS: The Old Guard Still Holding On Then there's NAS. You know, the traditional way: a couple of head nodes with a shared disk shelf, exporting NFS or iSCSI to your Proxmox cluster. It works. It's familiar. And in many ways, it's still a solid choice for certain setups. If you've got a solid HA-capable NAS (TrueNAS, XigmaNAS, Synology, etc.) and the proper dual-head redundancy, you can achieve real high availability on the storage layer. The trick is doing it right. But here's the catch: Open-source options for true HA NAS are limited. TrueNAS, for instance, only offers high availability on their proprietary hardware. Others like XigmaNAS do support CARP/HAST setups, but they're not exactly plug-and-play. You'll be getting your hands dirty with FreeBSD quirks and tuning scripts manually. Even if you pull it off, your Proxmox nodes are still tied to external storage - so you lose a lot of the benefits of hyper-convergence, like simplified scaling and fault tolerance. Also, performance can be hit-or-miss. While some setups with fast SSDs and high-speed links can hold their own, Ceph in a properly distributed setup has proven to outperform many commercial NAS appliances in both throughput and resilience. --- ## The Elephant in the Server Room: Bad Expectations One common thread across all these discussions? Misconfigured hardware. It's almost a trope now: someone buys eight compute nodes with tiny SSDs and a single "storage beast" with 200TB, then wonders why their Ceph setup is acting weird. Or they blow $700k on SQL licenses for a box with 96 underclocked cores because "more is better," without realizing their workloads don't scale that way. As one DBA savagely put it: "HA = Head Up Ass." He's not wrong. The best storage strategy in Proxmox often comes down to this: build for the architecture you're actually using. Don't wedge Ceph into a centralized storage model. Don't expect ZFS to be Ceph. And don't assume NAS will scale like distributed storage just because the GUI has an HA checkbox. --- ## So, Which Should You Use? Let's break it down by scenario: ### Use Ceph if… - You're running 3+ nodes with similar specs - You want true high availability and automatic failover - You can wire up high-speed networking (25Gbps or better preferred) - You're OK with a learning curve (or already comfortable with Proxmox and Linux) ### Use ZFS if… - You have a smaller cluster (2–5 nodes) - You can tolerate brief downtime in favor of simplicity - You want solid performance and built-in snapshotting - You're looking for a no-fuss way to get replication going fast ### Use NAS if… - You already have reliable dual-head NAS hardware - You're fine relying on external storage - You prefer centralized storage management - You don't need cloud-scale flexibility --- ## Final Thoughts High availability isn't just about picking the right tool - it's about picking the right tool for your setup. Ceph, ZFS, and NAS each bring serious strengths to the table, but they can just as easily backfire if you deploy them carelessly. Don't fall into the trap of overengineering your cluster or copy-pasting someone else's architecture without understanding why it works. Take the time to assess your actual needs - uptime, budget, skill level, and scale - and then build a system that's not just highly available, but also maintainable. Because at the end of the day, the best HA setup is the one that doesn't wake you up at 3 a.m. with broken quorum and a blinking console cursor. ## Resources - [Proxmox Ceph Documentation](https://pve.proxmox.com/wiki/Deploy_Hyper-Converged_Ceph_Cluster) - [ZFS on Proxmox](https://pve.proxmox.com/wiki/ZFS_on_Linux) - [Proxmox Storage Configuration](https://pve.proxmox.com/wiki/Storage)