Public bug reported:
Kubuntu 26.04 LTS live ISO hangs indefinitely in the casper initramfs when
booted with no network.
The last line on the console reads: `Temporary failure resolving
'archive.ubuntu.com'`
I'm filing against casper because the live boot appears to stall before systemd
starts.
Claude Opus 4.7 helped me debug this, and helped me write the bug
report. I've verified that the information is correct.
On a machine with no network connectivity (no Ethernet cable, onboard LAN
disabled in BIOS, no Wi-Fi/NIC present), the Kubuntu 26.04 LTS live USB hangs
forever during the live-boot/initramfs stage. The last line printed to the
console is:
Temporary failure resolving 'archive.ubuntu.com'
The boot never proceeds past this point (left running for over an hour).
The Kubuntu 24.04 LTS live image boots to the desktop on the exact same
hardware without any issue, with no network.
Steps to reproduce:
1. Write the Kubuntu 26.04 LTS live ISO to a USB stick (ISO SHA256 verified
against the published checksum; USB contents verified good).
2. Ensure the machine has NO network: no Ethernet connected, onboard LAN
disabled in BIOS, no Wi-Fi or add-in NIC present.
3. Boot the live USB.
Expected: the live session boots to the desktop without requiring a network
connection.
Actual: the boot hangs indefinitely; the last console message is "Temporary
failure resolving 'archive.ubuntu.com'".
The hang occurs BEFORE the real-root systemd starts (i.e. in the casper
initramfs):
- Adding "systemd.unit=multi-user.target" and "systemd.unit=emergency.target"
to the kernel command line made NO difference — the boot still ran up to the
same "Temporary failure resolving" line and hung identically. emergency.target
starts no networking/apt, so if it had been honored the apt line would never
appear. This indicates the stall happens before systemd target selection,
during the casper initramfs network/apt step.
- The kernel is alive at the hang: Magic SysRq responds. SysRq+T (show all
tasks) lists every task in S (interruptible sleep) or I (idle) state; none in D
(uninterruptible) or R (running). The system is parked waiting on a network
operation that never completes offline, not stuck in a syscall and not a
hardware freeze.
- Keyboard LEDs do not toggle during the hang, but Ctrl+Alt+Del and Magic SysRq
both work (a USB-keyboard LED-feedback quirk, not a true freeze).
Ruled out:
The hang is independent of all of the following (reproduced identically with
each, kernel parameters placed before the "---" separator):
- Boot media: ISO SHA256 verified; "toram" makes no difference.
- Graphics: "nomodeset" makes no difference.
- ACPI: "acpi=off" makes no difference.
- RAM: reproduced with each of the four memory modules individually, in the
manufacturer-recommended primary slot (A2), and with all modules installed.
- Network hardware: onboard LAN disabled in BIOS, no NIC present.
- The same hardware boots an existing older Kubuntu install (to recovery
console) and the Kubuntu 24.04 LTS live image without issue.
Workaround: Kubuntu 24.04 LTS live boots and installs normally on this
hardware with no network.
Hardware:
- Motherboard: MSI (AMI BIOS version A.10)
- CPU: Intel Core i7-8700 3.2GHz, supports x86-64-v3 (sse4_2, popcnt, avx, avx2)
- GPU: Intel UHD Graphics 630 (integrated)
- RAM: 56 GB (3 x 16 GB + 1 x 8 GB), 54 GiB usable. I also tried with only one
memory stick at a time, all four sticks, nothing changed.
- Storage: 2 x SATA HDD (one for `/` and one for `/home/`)
- Network: none active (onboard LAN disabled in BIOS)
Note that apport/ubuntu-bug logs could not be attached because the
affected live image never reaches a state where they can be collected.
** Affects: casper (Ubuntu)
Importance: Undecided
Status: New
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https://bugs.launchpad.net/bugs/2153452
Title:
Kubuntu install hangs with no network
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