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Ubuntu’s GRUB Change: Fixing a Problem… or Creating One

At some point, it stopped being “load kernel and go” and turned into this thing that tries to understand every filesystem, every storage setup, encryption, all of it, before the system is even running. And that’s where it keeps biting people. If you’ve dealt with GRUB breaking, it’s almost never the basic path. It’s trying to read something slightly non-standard and just falling over. Btrfs layouts, LVM stacking, and encrypted setups, stuff that works fine once the kernel is up, but GRUB has to guess at it first. The more GRUB understands, the more it can get wrong. This isn’t about “GRUB is bad,” it’s that GRUB turned into something way bigger than a bootloader, and now it carries all the risk that comes with that. . What Actually Changed? GRUB is getting stripped down specifically for Secure Boot scenarios. It will stop understanding filesystems like Btrfs, ZFS, and XFS, along with LVM and LUKS. None of that capability disappears from Linux, but it disappears from the stage before the kernel starts. GRUB now expects a direct, unencumbered path to the kernel. If it can’t read where the kernel lives because it's buried under an encryption layer it no longer understands, hence, you don’t boot. They are essentially trying to make GRUB act like a Unified Kernel Image (UKI) without actually switching the backend for everyone. So if GRUB Is the Problem… Why Not Just Move Past It? What keeps coming up with Ubuntu 26.10 Secure Boot is simple. There are already modern tools like systemd-boot, EFI stub, and UKIs. These options are much simpler by design. They do not try to understand complex filesystems or encryption. They just find the kernel, hand off control, and let the Linux kernel do the heavy lifting. Moving to one of these would be a "clean break" from the old way of doing things. So why is Ubuntu 26.10 sticking with a stripped-down GRUB? It comes down to compatibility. Ubuntu is a "run everywhere" operating system. It still has to support: Old computers with legacy BIOS (which can't use systemd-boot). Massive server environments with mixed hardware. Edge-case setups that the more modern, "simple" bootloaders aren't ready for yet. Because Ubuntu refuses to drop support for those older systems, they are stuck with GRUB. But because they want the security of a simpler boot process, they are "gutting" GRUB instead of replacing it. The result is an awkward middle ground. Ubuntu is keeping the same old bootloader in the middle of the chain, but it's stripping away the "intelligence" people actually rely on. So, no, they aren't moving past the problem. They are just trying to patch the problem. And that works fine right up until you try to carry an existing system forward. The Real Risk Isn’t New Installs. It’s Upgrades! If you’ve got an existing system with /boot sitting inside LUKS or layered through LVM, GRUB today can read through that. After this change, it can’t. The "Upgrade Trap" is simple: the upgrader will check your layout, see that it’s "unsupported," and stop the process entirely. You are effectively stranded on an old release unless you’re willing to manually repartition a live system. Routine upgrades are being traded for high-stakes recovery scenarios. If someone ignores the block and pushes through, the outcome is predictable: a system that doesn't boot and a long night with a Live ISO. Impact on Snapshot-Based Workflows Take away GRUB's filesystem logic, and you take away its ability to list snapshots. For Btrfs users, recovery goes from “pick a snapshot and boot” to a manual nightmare. Encrypted disks, LVM, Btrfs. These aren't "niche" setups. They are how real servers and advanced desktops are built. Why This Change Raises Real Concerns for Linux Users GRUB used to act like a file explorer at boot. It could read Btrfs, ZFS, and LUKS, determine where the kernel was located, and hand off cleanly. Now, it expects the kernel to be in a simple, directly readable location likea plain /boot partition. The complexity doesn’t go away; it just shifts. GRUB does less, while the kernel and initramfs do more. The problem is, if that later stage fails to mount your encrypted or layered storage, you aren’t in a GRUB rescue shell anymore. You’re dropped straight into the dreaded BusyBox shell. Instead of a bootloader with some "intelligence," you’re left in a minimal environment with almost no tools to fix a broken mount. While GRUB was a "safety net" you could interact with, the new model leaves you with almost no tools if the handoff fails. This Isn’t Just a GRUB Change; It Touches the Boot Process The boot process is the most sensitive layer of the system. Small changes here don’t fail cleanly; they fail early. When that happens, you’re not troubleshooting an app. You’re in recovery, trying to fix why the system won’t boot. For users who value stability, this "streamlining" feels like removing the safety net. Existing Systems Aren’t Clean or Standard Real-world systems evolve. Encryption gets added years after an install, storage gets reworked, and layers build up over time. A lot of setups work today precisely because GRUB is smart enough to handle that complexity. This change assumes a "clean" layout that simply doesn't match the messy reality of long-running Linux machines. Upgrades Could Become Recovery Scenarios This stops being a simple “update and reboot” task. If your layout doesn’t match what this new version of GRUB can read, you’re looking at moving /boot, separating encryption layers, or restructuring partitions just to get the system back up. One mistake during this manual restructuring, and your upgrade is now a full-blown recovery mission. This Pulls Boot Design Back Toward Older Models Separate, unencrypted /boot partitions are becoming the mandatory "safe" default again. It feels like 2010 called and wants its partitioning scheme back. We spent the last decade moving away from theserigid, fragmented layouts for a reason—they add friction and waste space. But, this change effectively mandates them if you want a system that "just works" under Secure Boot. Simpler defaults might help the majority, but they come at the cost of the flexibility that made Linux powerful. GRUB does less, the kernel does more, and the gap in between is where admins and power users end up doing the heavy lifting. If GRUB Is Too Complex… What’s the Endgame? On one side, you’ve got the appliance model. Simple, predictable, fewer moving parts, easier to lock down. On the other, how a lot of systems actually look. Layered storage, encryption, and setups that evolve over time instead of staying clean. Ubuntu is trying to sit in the middle. Keep GRUB, but strip it down. Reduce what it has to deal with early, while still supporting everything later. If GRUB isn’t handling it anymore, then your layout has to be simpler, or you’re dealing with it during recovery. As 26.10 gets closer, the question isn’t whether boot is simpler. It’s who ends up dealing with what got pushed out of it. . Significant GRUB changes in Ubuntu 26.10 present risks during upgrades and impact complex setups.. GRUB updates Ubuntu Secure Boot Linux upgrades recovery. . Dave Wreski

Mar 26, 2026 • Dave Wreski Server Security