[GDX] initramfs 345MB causes GRUB "out of memory" on 1GB /boot partition

[RaimondoMorosini]

Describe the bug
On bluefin-gdx:lts (stream10.1, 2026-04-07), the initramfs for kernel
6.19.7-100.fc42.x86_64 is 345MB. On systems with the standard 1GB /boot
partition, GRUB fails to load it with:

error: ../../grub-core/kern/mm.c:552:out of memory.

followed by kernel panic: VFS: Unable to mount root fs on unknown-block(0,0)

The previous deployment (stream10.1, 2025-09-16, kernel 6.12.0) had a
244MB initramfs and booted correctly.

Root cause
The GDX initramfs includes all GPU drivers (nvidia, amdgpu, radeon, i915,
xe, nouveau) + ZFS uncompressed, totaling 345MB. On a 1GB /boot partition
with two deployments, this leaves no room for GRUB to operate.

/boot size: 959MB
initramfs: 345MB ← too large
vmlinuz: 18MB
/boot free: 287MB ← insufficient for GRUB

Proposed fix
Add a dracut config in the GDX Containerfile:

RUN echo 'compress="zstd -19 -T0"'
> /usr/lib/dracut/dracut.conf.d/99-gdx-slim.conf &&
echo 'omit_drivers+=" amdgpu radeon i915 xe "'
>> /usr/lib/dracut/dracut.conf.d/99-gdx-slim.conf

GDX targets Nvidia+CUDA workloads — AMD/Intel GPU drivers in the initramfs
are unnecessary and add ~130MB. With zstd compression and nvidia-only
drivers, the initramfs drops from 345MB to ~157MB (tested locally).

Workaround (tested)
Manually regenerate the initramfs after boot from ostree:1:

sudo dracut
--force
--compress "zstd -19 -T0"
--omit-drivers "amdgpu radeon nouveau i915 xe"
--omit "fips"
--kmoddir /sysroot/ostree/deploy/default/deploy//usr/lib/modules/
--kver
/boot/ostree//initramfs-.img

Environment

• Image: ghcr.io/ublue-os/bluefin-gdx:lts
• Version: stream10.1 (2026-04-07)
• Kernel: 6.19.7-100.fc42.x86_64
• /boot: 959MB partition (standard install)
• GPU: Nvidia (only)

containerfile-patch.txt
issue-body.md
99-gdx-slim.conf.txt

[bashilias]

i used your workaround to make a fix in #4768