Problem: "Host key verification failed." SSH error, broken devices

The udev device manager may create incorrect device permissions and cause problems with SSH's PRNG and TTY sessions on the OpenVZ platform - this guide explains how to identify whether your VPS is affected and correct the issue.

Troubleshooting Symptoms

The following error condition symptoms will appear together when this issue occurs.

• SSH Error: "Host key verification failed."
• Broken devices and/or device permissions under /dev
• pgrep udev reports udev is running

Causes

The udev package is installed by default with most Linux distributions - unfortunately, the VPSLink OpenVZ virtualization platform is not compatible with udev.

If you recently upgraded your Linux distribution in-place on your OpenVZ VPS this problem (and likely many others) will manifest - for this reason VPSLink strongly recommends that you avoid in-place distribution upgrades on OpenVZ and, instead, use the My.VPSLink.com Control Center to rebuild your VPS with an updated operating system template developed by VPSLink's systems administrators.

If you recently rebuilt or installed your OpenVZ VPS operating system and you have encountered this issue, please contact VPSLink Support for assistance to ensure that the issue is corrected on your VPS and in our Linux OS template repositories.

Resolution

1. Using the package management application for your distribution, remove the udev package
2. Enter cd /dev && MAKEDEV tty
3. Go to https://my.vpslink.com/ and restart your VPS