kernel panic after update 2.0.3 kernel 7.0.0-34 7.0.0-31 works

[aralsistemas]

Installed and working for weeks 2.0.2, new installation, BRTFS, on HP ProDesk 400 g5, i7-8700T, 32 Gb, 1 Tb SSD SATA.
Today accepted updates. It reboots and install updates... Next reboot: Kernel Panic, can't access sda4.
Boot from previous kernel 7.0.0-31. It says Anduin 2.0.3, works well with this kernel.

¿Should I wait for another kernel? ¿How can I troubleshoot this situation?
Thanks.

[aralsistemas]

Update:
The file on /boot/initrd.img-7.0.0-34-generic does not exist. There is a link initrd.img to this file, but the file is not on /boot.
I suppose this is the error.
Currently searching for a way to reinstall 7.0.0-34.

Question: it seems /boot is on / partition so there is no limitation of space (more than 800 Gb free) and only 7.0.0-31 and 7.0.0-30 images. ¿Is there another space limitation for /boot?

[aralsistemas]

Update (2)
Found /var/unattended-upgrades/unattended-upgrades-dpkg.log:
Contents:
Log started: 2026-09-28 08:17:41
Disk Snapshots Manager package hook pre: transaction 38e689aa-017a-423e-b92e-c1f1c0787c78 is Complete
Disk Snapshots Manager package hook pre: transaction 668d2af7-62aa-4b37-a083-0c2f6a8ee70d is Complete

• synosnap dpkg pre hook check
  dumping distro info
• synosnap dpkg pre hook check
  dumping distro info
  (Leyendo la base de datos ...
  (Leyendo la base de datos ... 5%
  (Leyendo la base de datos ... 10%
  (Leyendo la base de datos ... 15%
  (Leyendo la base de datos ... 20%
  (Leyendo la base de datos ... 25%
  (Leyendo la base de datos ... 30%
  (Leyendo la base de datos ... 35%
  (Leyendo la base de datos ... 40%
  (Leyendo la base de datos ... 45%
  (Leyendo la base de datos ... 50%
  (Leyendo la base de datos ... 55%
  (Leyendo la base de datos ... 60%
  (Leyendo la base de datos ... 65%
  (Leyendo la base de datos ... 70%
  (Leyendo la base de datos ... 75%
  (Leyendo la base de datos ... 80%
  (Leyendo la base de datos ... 85%
  (Leyendo la base de datos ... 90%
  (Leyendo la base de datos ... 95%
  (Leyendo la base de datos ... 100%
  (Leyendo la base de datos ... 367863 ficheros o directorios instalados actualmente.)
  Desinstalando linux-modules-nvidia-580-7.0.0-30-generic (7.0.0-30.30) ...
  linux-image-nvidia-7.0.0-30-generic: removing .ko files
  Desinstalando linux-objects-nvidia-580-7.0.0-30-generic (7.0.0-30.30) ...
  Configurando synosnap (0.12.10) ...
  �[0;31m�[43mSYNO_AGENT_INSTALL_FOLDER is not set�[0m
  dpkg: error al procesar el paquete synosnap (--configure):
  old synosnap package postinst maintainer script subprocess failed with exit status 1
  Configurando linux-image-7.0.0-34-generic (7.0.0-34.34) ...
  Configurando linux-headers-7.0.0-34-generic (7.0.0-34.34) ...
  /etc/kernel/header_postinst.d/dkms:
  Sign command: /lib/modules/7.0.0-34-generic/build/scripts/sign-file
  Signing key: /var/lib/dkms/mok.key
  Public certificate (MOK): /var/lib/dkms/mok.pub

Autoinstall of module synosnap/0.12.10 for kernel 7.0.0-34-generic (x86_64)
Running the pre_build script.......... done.
Building module(s)...(bad exit status: 2)
Failed command:
make -j12 KERNELRELEASE=7.0.0-34-generic -C /lib/modules/7.0.0-34-generic/build M=/var/lib/dkms/synosnap/0.12.10/build KVER=7.0.0-34-generic modules

Error! Bad return status for module build on kernel: 7.0.0-34-generic (x86_64)
Consult /var/lib/dkms/synosnap/0.12.10/build/make.log for more information.

Autoinstall on 7.0.0-34-generic failed for module(s) synosnap(10).

Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
run-parts: /etc/kernel/header_postinst.d/dkms exited with return code 1
dpkg: error al procesar el paquete linux-headers-7.0.0-34-generic (--configure):
old linux-headers-7.0.0-34-generic package postinst maintainer script subprocess failed with exit status 1
dpkg: problemas de dependencias impiden la configuración de linux-headers-generic-hwe-26.04:
linux-headers-generic-hwe-26.04 depende de linux-headers-7.0.0-34-generic; sin embargo:
El paquete `linux-headers-7.0.0-34-generic' no está configurado todavía.

dpkg: error al procesar el paquete linux-headers-generic-hwe-26.04 (--configure):
problemas de dependencias - se deja sin configurar
dpkg: problemas de dependencias impiden la configuración de linux-generic-hwe-26.04:
linux-generic-hwe-26.04 depende de linux-headers-generic-hwe-26.04 (= 7.0.0-34.34); sin embargo:
El paquete `linux-headers-generic-hwe-26.04' no está configurado todavía.

dpkg: error al procesar el paquete linux-generic-hwe-26.04 (--configure):
problemas de dependencias - se deja sin configurar
dpkg: problemas de dependencias impiden la configuración de anduinos-kernel-parameters:
anduinos-kernel-parameters depende de linux-generic-hwe-26.04; sin embargo:
El paquete `linux-generic-hwe-26.04' no está configurado todavía.

dpkg: error al procesar el paquete anduinos-kernel-parameters (--configure):
problemas de dependencias - se deja sin configurar
Procesando disparadores para linux-image-7.0.0-34-generic (7.0.0-34.34) ...
/etc/kernel/postinst.d/dkms:
Sign command: /lib/modules/7.0.0-34-generic/build/scripts/sign-file
Signing key: /var/lib/dkms/mok.key
Public certificate (MOK): /var/lib/dkms/mok.pub

Autoinstall of module synosnap/0.12.10 for kernel 7.0.0-34-generic (x86_64)
Running the pre_build script............ done.
Building module(s)...(bad exit status: 2)
Failed command:
make -j12 KERNELRELEASE=7.0.0-34-generic -C /lib/modules/7.0.0-34-generic/build M=/var/lib/dkms/synosnap/0.12.10/build KVER=7.0.0-34-generic modules

Error! Bad return status for module build on kernel: 7.0.0-34-generic (x86_64)
Consult /var/lib/dkms/synosnap/0.12.10/build/make.log for more information.

Autoinstall on 7.0.0-34-generic failed for module(s) synosnap(10).

Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
run-parts: /etc/kernel/postinst.d/dkms exited with return code 1
dpkg: error al procesar el paquete linux-image-7.0.0-34-generic (--configure):
old linux-image-7.0.0-34-generic package postinst maintainer script subprocess failed with exit status 1
Se encontraron errores al procesar:
synosnap
linux-headers-7.0.0-34-generic
linux-headers-generic-hwe-26.04
linux-generic-hwe-26.04
anduinos-kernel-parameters
linux-image-7.0.0-34-generic

• synosnap dpkg post hook check
  dumping distro info
  compare distro info
  check for file trigger
• synosnap dpkg post hook check
  dumping distro info
  compare distro info
  prehook env or posthook env missing, skip compare
  check for file trigger
  E:Sub-process /usr/bin/dpkg returned an error code (1)
  Log ended: 2026-09-28 08:18:49

---

It looks module synosnap fails. I'll try to uninstall this module. It is an agent from Synology Active Backup for taking snapshots to a synology NAS.
I could not install at all. May be it is not compatible with btrfs.

[aralsistemas]

Update (3)
uninstalled synosnap module: sudo dpkg -r synosnap
sudo apt update
sudo apt upgrade (has installed kernel 7.0.0-34 again)
reboot
Working now with kernel 7.0.0-34
Resolved

[Anduin2017]

Ack. Will take a look soon.

[Anduin2017]

Thank you for investigating this so thoroughly and, especially, for posting the fix. I’m glad your system is booting normally again with kernel 7.0.0-34-generic.

The logs point to an interrupted kernel installation rather than a defect in that kernel or a lack of free space in /boot.

The third-party Synology synosnap package failed to configure, and its DKMS module failed to build for 7.0.0-34. That stopped the kernel installation hooks before the matching /boot/initrd.img-7.0.0-34-generic could be generated. The initrd.img then pointed to a file that did not exist, which explains why the new kernel could not access the root filesystem.

I will not take action to the source code of AnduinOS since this is not an issue with AnduinOS itself.