Assistance with Kernel Panic on VPS

iPwsite

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May 9, 2020
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25
Hello,
I have recently installed DirectAdmin on my Contabo VPS and completed the CustomBuild process successfully. The installation finished without errors, and I rebooted the VPS as instructed.

However, after reboot, the VPS failed to boot properly and I encountered a kernel panic.

Error message shown in VNC:

Unable to mount root fs on unknown-block(0,0)

I am accessing the VPS via VNC (RealVNC Viewer on macOS) since SSH is no longer available after the crash.




What I did before the issue​


  • Fresh install of DirectAdmin on a Contabo VPS
  • Web server: Apache + PHP-FPM + PHP 8.3
  • Database: MariaDB
  • FTP: PureFTPd
  • CustomBuild installation completed successfully
  • Rebooted the VPS → immediately hit kernel panic



My Questions​


  1. Is this a known issue related to kernel parameters modified during DirectAdmin’s CustomBuild?
  2. How can I fix the kernel panic from VNC (e.g., boot into recovery, reinstall grub, or mount root properly)?
  3. If needed, is there a safe way to reinstall the kernel without wiping the VPS?

I can not access the VPS Server via root.


Any guidance or recommended steps would be greatly appreciated 🙏.

Please check attached file.

Thank you,
 

Attachments

  • Screenshot 2025-09-28 at 17.34.32.png
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Thank you for your reply.

Could you please help to solve the issue if I share my root or via screenshare? My email is: [email protected]

I also installed AlmaLinux 9 on my Contabo VPS and rebooted the system. However, I am unable to log in to the server via SSH using [[email protected].(mailto:root@.247.183.**) from my Mac terminal.

Additionally, when I attempted to connect to the server via VNC (Virtual Network Computing), I encountered the issue shown in the attached file. The console output indicates that the system is failing to boot properly, with errors such as:

  • systemd[1]: Failed to execute /sbin/init, giving up: Exec format error
  • systemd[1]: Freezing execution
I have not taken any further steps to troubleshoot this issue yet.
 
That's an OS level issue as @zEitEr has said. Looking at that, your bootloader can't find or can't mount the / partition. Without this, it cannot continue. Might pop a ticket across to Contabo Support if I was you and they can look at your grub loader? They can probably fix the issue quicker than a forum.
 

2. Rocky Linux VPS Boot & SSH Login Issue​

Issue Summary:

  • OS Installed: Rocky Linux (version not specified, assumed 9)
  • Problem: Cannot log in via SSH (root@<IP>) from Mac terminal.
  • VNC Observation: Boot hangs after:
    • Probing EDD (edd=off to disable)... ok
  • Current Status: VPS does not reach full boot; SSH login fails.
Analysis:

  • Boot hang after EDD probing suggests kernel or bootloader configuration issues.
  • Could be similar to the AlmaLinux 9 issue, possibly due to differences in systemd/init compatibility or VPS virtual environment requirements.

1. AlmaLinux 9 VPS Boot Failure

Issue Summary:

  • OS Installed: AlmaLinux 9
  • Problem: Unable to log in via SSH (root@<IP>) from Mac terminal.
  • VNC Observation: Boot fails; console output shows errors:
    • systemd[1]: Failed to execute /sbin/init, giving up: Exec format error
    • systemd[1]: Freezing execution
  • Current Status: VPS does not reach a usable state; no further troubleshooting performed by user.
Analysis:

  • The Exec format error indicates the kernel or init system may be incompatible with the VPS architecture or boot configuration.
  • This is likely related to AlmaLinux 9 requiring additional VPS configuration that is not applied by default.

  • 3. AlmaLinux 8 – Successful DirectAdmin Installation

  • Issue Summary:
    • OS Installed: AlmaLinux 8
    • Action Taken: Installed DirectAdmin and rebooted VPS.
    • Result: System boots successfully, SSH login works as expected.
    • Analysis:
    • AlmaLinux 8 is fully compatible with the VPS environment and requires no additional configuration for boot or SSH access.
    • Suggests that the issues with AlmaLinux 9 and Rocky Linux 9 are likely due to changes in systemd, init, or kernel requirements in the version 9 line.
 
You won't be able to boot into your server via SSH if your server doesn't boot successfully as SSH is one of the OS services. Your only options are to try and boot into a rescue environment (whatever one Contabo uses) and check your drives, and the configuration. You'll have to use VNC or something similar due to lack of SSH. That's where I would start first.

Are you able to spin up another VPS with Contabo and see if the problem persists? Installing DA itself shouldn't cause any Kernel issues. Advice with new servers are to run the OS updates first via apt or yum (depends on what OS you're using) and then run the DA install script. That usually irons out any nasties before you install DA.
 
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