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TLC (Triple-Level Cell) and QLC (Quad-Level Cell) are the two NAND flash types behind most enterprise SSDs today. TLC stores 3 bits per cell, QLC stores 4. The extra bit gives QLC roughly a third more density per wafer, and typically twice the density per SSD, at the cost of random write speed and total write endurance. That tradeoff hasn’t changed. What’s changed is that the technology has advanced significantly, and QLC’s practical downsides are now small enough that the decision deserves more than a one-line answer. NAND flash contract prices are projected to climb another 55-60% quarter over quarter into 2026, on top of increases that have already topped 300% since 2025 . At that pricing, “just buy TLC, it’s the better NAND” stops being a simple recommendation and starts being a real budget decision. Here’s how the two actually compare, why QLC performs better than the spec sheet suggests, and how OpenZFS’s write path changes the calculation on TrueNAS specifically. NAND Flash: A Quick Refresher Flash memory stores data as voltage levels in floating-gate transistors, not as magnetic states on a spinning platter. The first SSDs used Single-Level Cell (SLC) NAND: one bit per cell, two possible voltage states, fast and durable but expensive per gigabyte. Multi-Level Cell (MLC) doubled density to 2 bits per cell. TLC and QLC pushed that further, to 3 and 4 bits per cell, by packing 8 and 16 distinct voltage states into the same physical cell. The more bits in a single cell, t

Run a TrueNAS pool long enough, and someone will warn you: stay under 80% full. The “80% rule” for capacity is like a ghost story of ZFS storage administration. Everyone has heard of it, but ask a room of admins why it exists, and the answers get vague fast. It gets passed around like hearsay: advice from a wise old sage, who heard it from another wise old sage, repeated until it becomes a mantra people cite without being able to justify it. The rule holds that ZFS pool performance degrades once utilization passes roughly 80%, driven by fragmentation, metaslab pressure, and, on spinning disk, LBA weighting. While the laws of physics apply to all filesystems, the TrueNAS and ZFS communities are often very interested in preserving not just the safety of their data, but reliable and consistently rapid access to it. Here’s what’s actually driving the slowdown. The Three Problems The performance penalty that started the 80% rule isn’t a single, monolithic problem. It’s a mix of three distinct phenomena, and how much they impact you depends entirely on what your storage is actually doing. Every file system has the complex task of mapping user data to specific physical locations on the disk – by using Logical Block Addresses (LBAs) the file system doesn’t need to know the exact geometry or layout of the physical storage media. As the media fills up, there is a secondary problem of housekeeping, and finding contiguous space to store new user data. When the free space is scattered acr

Patch notes are supposed to be boring. A short list of CVEs, a version bump, nothing to see here. That stopped being true the moment AI models got better at finding vulnerabilities than most people are at writing proof-of-concepts for them. TL;DR: TrueNAS 25.10.5 shipped last month with a normal batch of kernel CVE fixes. TrueNAS 25.10.6 ships fixes for more than 250 upstream CVEs just 19 days later, plus eight TrueNAS-specific fixes spanning Fibre Channel, NFS, and HA failover. None of them are flagged as under active exploitation in the official notes – but at this volume, batching fixes into the next scheduled release stops making sense. The Math Changed, Not TrueNAS Every OS vendor is living this right now, not just us. Microsoft’s July update alone patched over 600 CVEs – a volume that would have taken years to work through five years ago. Anthropic’s Project Glasswing found that its Claude Mythos model could autonomously surface thousands of previously unknown vulnerabilities across every major OS and browser, and Epoch AI has since tracked a 3.5x spike in disclosed CVEs . Older, less-scrutinized platforms aren’t safer by comparison. They just haven’t had a model pointed at them yet. TrueNAS isn’t exempt from that math, and pretending otherwise would be the actual security risk. What changes is how fast we act on what gets found. What’s Actually Fixed TrueNAS 25.10.6 bumps the Linux kernel from v6.12.95 to v6.12.99, the latest 6.12 LTS release, pulling in fixes for more

When one of the world’s largest grocery retailers moves to migrate 40,000 server workloads off its hypervisor stack while suing its software vendor for more than £100 million , enterprise IT takes notice. According to Tesco’s High Court filing, the retailer purchased perpetual licenses for VMware vSphere Foundation and Cloud Foundation in January 2021, with support intended to run through January 2026 and an option to extend. After Broadcom completed its acquisition of VMware in late 2023, Tesco says it was pushed toward subscription-only bundles priced far above the original agreement – court filings put the increase at more than 170%, with a replacement package priced roughly £15 million above the licenses Tesco says it already owns outright. Broadcom disputes Tesco’s characterization, and the case is still working through the UK High Court. “Faced with Broadcom’s abusive conduct, and given the criticality of virtualization… Tesco has been forced to incur material costs to procure alternative solutions.” — Tesco High Court filing Whatever the court decides, the exposure is already real: a corporate acquisition changed the terms of a five-year-old contract, and a retailer with no interest in a hypervisor migration is now running one at “exceptional pace.” The question worth asking before you’re in the same position: how much of your infrastructure would move with you if your hypervisor vendor changed the deal tomorrow? For many IT teams, the honest answer is “the hardware, a

Industry veteran with 3 decades of global technology leadership joins TrueNAS as CRO to lead worldwide sales strategy & expand partner-led enterprise adoption. CAMPBELL, CA, August 3, 2026 — TrueNAS, the enterprise storage platform trusted by more than 60% of the Fortune 500, doubles down on growth by appointing Jason Wakeam as Chief Revenue Officer (CRO). The strategic appointment comes at a pivotal moment in the enterprise storage market. Rising infrastructure costs — driven by memory-intensive AI workloads and expanding data volumes — are shifting storage decisions into strategic financial discussions involving CFOs and executive leadership. Organizations worldwide are actively seeking alternatives to legacy vendors whose architectural rigidity and recurring cost structures no longer align with long-term business requirements. Wakeam brings nearly three decades of global technology leadership experience to TrueNAS, with a proven track record of scaling revenue organizations, expanding market share, and building high-impact channel and partner ecosystems across public and private enterprise software and cloud infrastructure companies. He most recently served as Chief Revenue Officer at Backblaze, and previously held senior sales and partner leadership roles at SnapLogic, Cloudera, Hortonworks, Microsoft, and Hewlett-Packard. “TrueNAS has built tremendous momentum over the past several years and is entering its next phase from a position of strength: growing enterprise deman

“Compression saves space, but it costs performance.” That used to be true. It’s why plenty of admins still leave it off by default, or only turn it on for cold archive data where nobody will notice the tax. That math made sense when CPU was scarce and every cycle mattered. It doesn’t hold anymore. ZFS compression shrinks data before it’s written to disk and expands it again on read, so a dataset holds more data in the same physical space without changing how it’s accessed. The Old Math Doesn’t Work Anymore CPU has gotten cheap and plentiful – more cores, more threads, more headroom than most storage workloads ever touch. Storage hasn’t kept pace the same way. It’s still bound by latency, device wear, and the cost of physically moving bytes through the stack. That changes the question. It’s no longer “is compression worth the overhead?” It’s “is some idle CPU worth spending to avoid storage I/O you’re already paying for.” For most environments, yes. Compression in the Pipeline, Not in Post TrueNAS, built on OpenZFS , doesn’t bolt compression on as an afterthought – it’s part of the I/O path. Data is compressed before it’s written, so the space savings land immediately. No background job runs later to reclaim it. On read, data is decompressed just before it reaches the client, and every data-integrity and redundancy feature keeps operating on the compressed blocks underneath. The practical result is less data moving through your storage stack, and less data competing for room i

“Add more RAM” is the right answer to a slow storage system more often than not; but it’s also not always the answer you get to give. Budget caps it. Technical limitations of your motherboard cap it. Consolidating more workloads onto fewer nodes caps it hardest of all. At some point you’re running a working set bigger than the memory you’re allowed to put in the box, and no amount of wishing changes that math. When RAM runs out, TrueNAS lets you expand your cache with L2ARC , a second-level SSD-backed read cache that keeps reads fast when your working set outgrows RAM. That’s the situation OpenZFS was built to handle gracefully – not by pretending RAM is infinite, but by giving you a second tier when it isn’t. ARC is the cache that makes ZFS feel fast TrueNAS is built on OpenZFS, and the reason ZFS reads feel fast is the ARC – the Adaptive Replacement Cache, sitting in system RAM. ARC isn’t just holding recently-used data. It splits attention between data that’s been read once and might be read again soon, and data that’s genuinely marked hot from repeated access. It also tracks what data was evicted and how soon after eviction that data was read, to know whether that eviction was a “mistake” – which is what adds the “adaptive” to ARC. Rather than running on fixed rules and ratios, it dynamically corrects itself against your actual workload in real-time. When RAM is generous, this is close to the whole story. Reads come from memory, latency is close to zero; and nobody thinks

TrueNAS 25.10 is Production-grade With over 150,000 deployments, TrueNAS 25.10.4 has been thoroughly tested and is recommended for General and Mission-Critical users. Both our TrueNAS Community Edition users and Enterprise customers are now deploying and using this version by default. Quality is the best it’s ever been, with user counts continually growing, and reported issues at record lows. All healthy signs of a highly mature and battle-tested production release. With support for our full line of Enterprise appliances, including our flagship V-Series appliance , and offering new software integrations such as our new OpenShift driver , TrueNAS 25.10.5 is ready to handle your most demanding workloads. However, in the new AI world, it’s not only users who report issues. New AI models and AI-enhanced security researchers are actively looking for security vulnerabilities, which are then passed on to the TrueNAS team and other software developers. With this influx of new vulnerabilities, TrueNAS 25.10.5 is needed to defend and secure data. What’s Fixed in 25.10.5 TrueNAS 25.10.5 brings an updated Linux kernel version 6.12.95, which patches multiple security-related CVEs, including SharedFrag (CVE-2026-43503) and PeditCOW (CVE-2026-46331) local privilege escalation vulnerabilities, as well as six more upstream security fixes. Beyond the kernel, this release also delivers a number of TrueNAS specific fixes: A console memory leak was identified that could consume excess RAM Correct

Enterprise storage is usually evaluated on three familiar dimensions: performance, capacity, and price. Those metrics matter. But they leave out a more fundamental question: Can you trust the data? That question deserves a much bigger role in enterprise infrastructure decisions. Because not all storage failures look like outages. Some of the most dangerous problems are quieter than that. A system may stay online. Applications may keep running. Dashboards may still populate. Backups may still complete. And yet, somewhere beneath the surface, data may be corrupted, altered, or damaged in ways that are not immediately obvious. Unlike scheduled patrol reads on traditional RAID solutions, TrueNAS self-healing storage continuously verifies data against stored checksums, automatically repairing any block that no longer matches using its redundant copies. Corruption is caught and corrected before it reaches a backup, report, or decision. Every storage device has an accepted rate of failure, called the “Uncorrectable Read Error” rate, often shortened to “URE.” These rates are mathematically rare – typically 1 in 10 15 – so if you’re storing a small amount of data, the odds start in your favor – but the mathematical reality is that as total storage capacity and data access frequency grow, the probability of encountering these silent errors increases significantly. At multi-petabyte scale, it stops being theoretical – and becomes a routine occurrence. Because these issues happen at the

TrueNAS Connect is TrueNAS’s browser-based management service — it lets you deploy, monitor, and update TrueNAS systems from one dashboard instead of logging into each one separately. Eight months after launch, TrueNAS Connect is on its way to a three-tier structure: Foundation is completely free and covers up to 2 systems, with a web-based installer that simplifies getting a new TrueNAS system running. Plus launched in late January and is priced at $60 USD per year for up to 3 systems, with up to 1PB of combined capacity. It adds replication management, app and VM management, and continuous statistics collection with 30-day retention. For a limited time, a coupon code is available for a 50% discount on annual subscriptions . Business is in development for a Q4 launch, with support for HA systems and no cap on system count or capacity. It’s built for teams of admins, including MSPs, managing a fleet of TrueNAS systems. July Improvements Every update to TrueNAS Connect ships in the background – there’s nothing for users to install or configure. July’s release improves two things: Microsoft OAuth. Microsoft and Office 365 users can now set up and sign into their TrueNAS Connect accounts with their existing credentials, joining the Google and GitHub sign-in options already available. This improves both security and ease of setup for those users. WebUI alignment. The updated Connect interface now uses the same UI elements as TrueNAS 26, so the two interfaces feel like one continu

Hybrid storage combines high-capacity spinning disks with flash-based caching and metadata layers, so data gets HDD economics with SSD-like responsiveness where it matters most. The all-flash default made sense for a while. NVMe prices dropped fast enough that overprovisioning felt responsible. Why spend time designing careful storage tiers when flash was cheap enough to ignore the question? That logic expired somewhere around late 2025, when NAND supply constraints pushed flash prices significantly higher. Renewal quotes that looked reasonable 18 months ago now look like different documents. Organizations running flash-only platforms are finding out something uncomfortable; when your vendor only sells one tier, their supply chain exposure becomes your budget problem. Reach out to us today to see how TrueNAS compares to flash-only alternatives. The assumption that broke The “all-flash by default” architecture was always a cost argument dressed up as a performance argument. Flash is faster, so the pitch was simple – “just buy flash, and stop worrying.” What it glossed over is that most enterprise data doesn’t need flash performance. It just got priced like it did – because flash was cheap enough that the waste wasn’t visible. It’s visible now – and “just buy flash” is a distant memory. HDD vs. SSD Economics: Most of your data isn’t hot Look at a typical enterprise data footprint. Primary databases, VDI boot volumes, latency-sensitive transactional workloads – these genuinely b

We recently launched TrueNAS 26 BETA.1 , marking the first step towards our new annual release cadence. This shift replaces our previous twice-yearly software release schedule, and is designed to provide better quality, more predictable planning, and a clear path toward a 3-year Long-Term Support (LTS) release for our TrueNAS Enterprise customers. Today, we’re excited to announce the release of the next stage, with TrueNAS 26 BETA.2 . TrueNAS 26 is the upcoming release of our enterprise storage platform built on OpenZFS 2.4, designed to enable tiering between flash and spinning disk – reducing cost-per-TB without sacrificing performance – while adding native container workloads and browser-based file sharing to a single unified system. With BETA.2, we’ve focused on hardening the foundation laid by BETA.1, squashing bugs, and refining the features that define the TrueNAS 26 platform – including tiered storage, integrated search across up to a billion files, and native LXC container support. When TrueNAS 26 is the Right Move If you’re planning to upgrade from TrueNAS 25.x to TrueNAS 26, here’s what to expect for both performance and usability. TrueNAS 26 is built to address the modern challenges of “memflation,” AI-driven data demands, and the need for simplified, intelligent data services. Key improvements include: OpenZFS 2.4 : Delivering major hybrid pool improvements, including new dataset tiering and Fast Dedup enhancements. This allows you to balance flash performance wit