This guide demonstrates the steps to place a Linux-based VPS in an offline mode to recover from a kernel panic.
Before attempting any rescue, back up your VPS. Vultr offers manual snapshots and automated backups for VPS instances. If you do not have automatic backups enabled, make a manual snapshot. Attempting to rescue a server without a backup is reckless. There is no substitute for a sound backup strategy. You can create a server snapshot in a few clicks in the customer portal.
You are responsible to back up all your mission-critical data, following your local laws and organizational policies. Vultr does not maintain additional backups outside your customer portal.
Open the Vultr web console to view the server startup messages. If needed, click the Send CtrlAltDel button at the top-right of the console to reboot the server.
Take note of the error messages shown on-screen. The exact kernel panic error message will vary widely, depending on the Linux distribution, version, and nature of the problem. Research the internet for solutions to your particular error using keywords from your error messages.
Mounting the VPS filesystem requires a few steps:
Mount ISO and boot the VPS.
Connect to the VPS via SSH.
Identify the correct data device.
Mount the filesystem device.
The general troubleshooting guide, "Troubleshoot your VPS with Bootable ISOs" describes these steps. Once you have the filesystem mounted, you have access to the VPS files.
With full access to your filesystem, perform the resolution steps you identified when researching the error messages. To test your solution, unmount the ISO in the Vultr server information page, which also reboots the VPS.
If the problem is not resolved, continue to research the issue. Sometimes when attempting repairs, the problem deteriorates or becomes confusing, so it's good to have a backup to restore the original starting point.