SolusVM Xen server won’t boot

Every so often I have users who have an issue with their SolusVM server not booting when it was working just fine.  About 99% of the times it’s because they performed a yum upgrade and replace the kernel that caused their VPS to crash and fail boots.

We run Xen with paravirtualization and i’ve seen many times where kernel changes cause the users VPS to not work after reboots.

Fixing Crashed Xen VPS

This is how I got about checking and fixing the VPS, if the serial console isn’t available.

Login to the  SolusVM admin panel and find the VPS account that has an issue.

Make note of the node it’s on and VPS name, in my case it’s on cloudvm6 and name is vm184

Log into node server

ssh root@cloudvm6.example.com

Now lets manually start the VPS and see what errors we get on console

[root@cloudvm6 xen]# xm create -c /home/xen/vm184/vm184.cfg 

This customer has a number of kernels installed.

    pyGRUB  version 0.6
 ┌────────────────────────────────────────────────────────────────────────┐
 │ CentOS (2.6.32-696.18.7.el6.i686)                                      │
 │ CentOS (2.6.32-696.3.2.el6.i686)                                       │
 │ CentOS (2.6.32-696.1.1.el6.i686)                                       │
 │ CentOS (2.6.32-642.11.1.el6.i686)                                      │
 │ CentOS (2.6.32-642.6.2.el6.i686)                                       │
 │                                                                        │
 │                                                                        │
 │                                                                        │
 └────────────────────────────────────────────────────────────────────────┘
     Use the ^ and v keys to select which entry is highlighted.
     Press enter to boot the selected OS. 'e' to edit the
     commands before booting, 'a' to modify the kernel arguments
     before booting, or 'c' for a command line.

So lets select the original kerne, and see if the server boots up.

Yes that was the issue, VPS booted to a prompt so the customer can login.  They will need to set their grub boot kernel to the right version before making future reboots.