Troubleshooting Ubuntu Server 24.04 OOM GRUB Error on Dell

Problem Statement

Ubuntu Server 24.04 LTS (Noble Numbat) installation media can stall at the GRUB stage with an error: out of memory message on a range of Dell systems. Unlike a kernel panic, the failure surfaces in the early pre-kernel bootloader phase, before initrd handoff, and is characterized by an apparent hang of 45 minutes to 1 hour before the boot sequence either recovers or fails outright. Operators typically encounter the condition when performing a clean install from USB media, when re-imaging a previously used disk, or when attempting an upgrade on systems that have non-default UEFI memory layouts.

The symptom presents as a frozen GRUB menu or a black screen with the literal string error: out of memory printed one or more times. The cursor does not advance, no kernel is loaded, and the installer never launches subiquity. The condition is reproducible across reboots and is independent of the target drive selection, which is why traditional partition-level troubleshooting steps fail to resolve it.

Dell documents this behavior in the official Ubuntu 24.04 release notes as a known issue affecting systems running the OEM factory image and standalone installs of the 24.04 media. The release notes confirm the timing window of 45 minutes to 1 hour at the GRUB level and apply to multiple Dell platforms certified for Ubuntu Server.

Affected Configurations

Root Cause Analysis

The out of memory condition is initiated in the GRUB 2 environment, which runs in a constrained memory window before the Linux kernel takes over. GRUB reads its own memory map from the UEFI firmware and reserves a region for the kernel image, initrd, and command-line parameters. On the affected Dell firmware revisions, the memory map returned to GRUB either under-reports the available lower-memory region or advertises fragmented regions that GRUB cannot coalesce.

Two distinct memory allocation paths can fail:

1. Initrd load failure: GRUB attempts to load the compressed initrd.img for the HWE kernel (6.8.x for 24.04). The image exceeds the contiguous free region below the 4 GB boundary. The error is printed, GRUB retries from a higher address, and the cycle repeats until a successful allocation is found or the firmware reclaims the region.
2. Command-line buffer failure: GRUB allocates the kernel command line as a single contiguous buffer. If the firmware advertises a high-memory map that excludes low memory, the allocation cannot be satisfied and the retry logic engages.

The documented 45-60 minute recovery window corresponds to GRUB's internal retry loop, which polls the firmware memory map at intervals and attempts to relocate its own heap once the firmware reclaims transient allocation regions used during POST. Operators observing a hang should treat the message as informational and allow the retry loop to complete.

Pre-Installation Diagnostics

Run the following checks before re-attempting the install. These isolate the failure from environmental causes that present as identical symptoms.

Verify Media Integrity

Download the SHA-256 checksum from the Ubuntu releases server and compare it to the value computed from the ISO or written USB image.

# Compute checksum on Linux/macOS
sha256sum ubuntu-24.04.3-live-server-amd64.iso

# Compute checksum on Windows (PowerShell)
Get-FileHash .\ubuntu-24.04.3-live-server-amd64.iso -Algorithm SHA256

If the checksum does not match, the failure is media-related, not memory-related. Re-download and re-write the image.

Verify Hardware Memory

Boot the Dell hardware into its built-in diagnostics (typically F12 at POST) and run the full memory test. Memory faults can produce out of memory errors at GRUB that are unrelated to the Ubuntu 24.04 known issue.

Capture the UEFI Memory Map

From the UEFI shell (if available) or by booting a Linux live environment from a separate USB, capture the firmware memory map:

# Linux live environment
sudo dmesg | grep -i 'efi: mem' | head -40
sudo cat /proc/iomem | head -60

Compare the output to a known-good boot of the same hardware. Look for missing low-memory regions (below 4 GB) or excessive reserved regions assigned to PCI BARs.

Workarounds

Apply the workarounds in the order listed. Each one addresses a distinct trigger and several can be combined.

Workaround 1: Allow the Retry Loop to Complete

On systems where the OOM message appears and the screen remains static, leave power applied and the installer unattended for at least 75 minutes. GRUB will eventually satisfy the allocation and proceed to the kernel handoff. This is the lowest-risk resolution and the one recommended by Dell for the documented known issue.

Workaround 2: Disable Network During Install

Disconnect the Ethernet cable before booting the installer. The 24.04 subiquity installer contacts the Ubuntu archive during the early phase to fetch updated packages and installer components. On systems with a slow or restricted link, the parallel fetch competes with the GRUB memory pool and increases the probability of the OOM retry loop. With the network disconnected, subiquity operates in fully offline mode and the boot proceeds without the archive fetch.

# Confirm link state before boot
ip link show eth0 | grep state

Workaround 3: Wipe the Target Drive

If the target drive previously contained another OS, the GPT/MBR partition map can interfere with the installer's partition probe. Wipe the drive from a separate live environment before launching the installer:

# Identify the target disk
lsblk -d -o NAME,SIZE,MODEL,SERIAL

# Wipe partition table and filesystem signatures
sudo wipefs -a /dev/nvme0n1
sudo sgdisk --zap-all /dev/nvme0n1

# Optional: secure erase of SSD (non-recoverable)
sudo nvme format /dev/nvme0n1 --ses=1

Workaround 4: Use BalenaEtcher for Media Creation

Rufus writes the ISO in DD mode by default, but its handling of the Ubuntu hybrid image can leave an extraneous partition marker on the USB. BalenaEtcher performs a stream copy and writes a single, clean partition map:

1. Download BalenaEtcher from the official site.
2. Select the Ubuntu 24.04.3 ISO.
3. Select the target USB device.
4. Click Flash and wait for validation to complete.

Workaround 5: Boot the Live Environment First

If the installer fails to launch, try booting the live server environment directly to confirm the media and hardware are functional:

1. At the GRUB menu, press e to edit the default entry.
2. Locate the line beginning with linux.
3. Append memtest=1 to the kernel command line for a memory probe, or remove quiet splash for verbose boot output.
4. Press Ctrl+X or F10 to boot.

Workaround 6: Adjust UEFI Memory Settings

From the Dell UEFI setup (F2 at POST):

1. Disable Above 4G Decoding temporarily. Some firmware revisions mishandle the 64-bit PCI aperture and starve GRUB of low memory.
2. Set Memory Map or Memory Remap to Enabled if the option is present and currently disabled.
3. Save and exit, then attempt the install.

Workaround 7: Try an Alternate USB Port or Device

USB 3.2 ports on certain Dell platforms share bandwidth with the chipset's SATA controller. A USB 2.0 port on a rear I/O cluster typically provides a more stable enumeration path. Replace the USB stick with a different model if the failure persists across multiple ports.

Workaround 8: Try a Different Distribution

Boot a different Linux distribution (Debian 12, Ubuntu 22.04 LTS) to confirm the failure is specific to the Ubuntu 24.04 media and not a hardware fault. A successful boot of an alternate distribution on the same hardware eliminates the USB, port, and firmware from the suspect list.

Decision Tree

Verification

After the installer completes, confirm the install is healthy and the OOM condition has been resolved:

1. Boot the installed system and verify the kernel loaded cleanly:

   journalctl -b 0 | grep -i 'memory\|grub\|efi' | head -20

2. Confirm GRUB is installed to the correct device:

   sudo grub-probe --target=drive /boot/grub
   sudo efibootmgr -v   # UEFI systems only

3. Verify initrd generation:

   ls -lh /boot/initrd.img-$(uname -r)
   update-initramfs -c -k $(uname -r)

4. Reboot twice and confirm the GRUB menu resolves within 10 seconds with no OOM message.

Preventive Measures

• Maintain a verified offline copy of the Ubuntu 24.04 ISO with SHA-256 recorded in your asset register.
• Standardize on BalenaEtcher for USB media preparation across the engineering team.
• Document the UEFI firmware revision for each Dell target and track it against the Ubuntu 24.04 known issues list at the start of each deployment cycle.
• Build a provisioning checklist that includes the disconnect-network step for the first boot, even on systems that do not exhibit the OOM message.
• Keep a bootable rescue USB (Ubuntu 22.04 LTS or Debian 12) on hand so a stuck 24.04 install can be recovered without a second USB stick.

Related Parameters

Field Notes

The OOM retry loop in GRUB 2.12 is silent except for the single error: out of memory print. There is no progress indicator, no spinner, and no log file. Operators who are not aware of the 45-60 minute window will power-cycle the system repeatedly, which both resets the timer and risks leaving the USB media in an inconsistent state. The most important field note is the simplest: if the message is present and the cursor has not advanced for less than 75 minutes, do not interrupt.

The condition is also sensitive to the order in which USB devices enumerate. A keyboard or mouse on a USB 3.2 hub can shift the enumeration timing enough to change whether GRUB finds a free contiguous region. On systems with persistent OOM after the retry window, disconnect all non-essential USB peripherals before the next boot attempt.

For automation scenarios, the OOM condition can be detected by polling the serial console (if configured in UEFI) for the literal string error: out of memory and then entering a wait state for 75 minutes before issuing a reboot. This preserves the recovery path and avoids the reset-loop trap.

FAQ