A new KVM VPS created in SolusVM is not working: This usually means your kernel doesn't support virtio, or supermin was unable to load some kernel modules

Symptoms 

• A new KVM VPS is not working - the VPS is online but in VNC console there is an error:

  CONFIG_TEXT: No bootable device

• When running libguestfs-test-tool in KVM Slave node there is an error:

  # libguestfs-test-tool
  supermin: mounting /sys
  [ 1.826148] input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input2
  [ 2.135668] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x6d5b6741cee, max_idle_ns: 881590928851 ns
  [ 2.139190] clocksource: Switched to clocksource tsc
  supermin: waiting another 1024000000 ns for /sys/block/sdb/dev to appear
  This usually means your kernel doesn't support virtio, or supermin was unable
  to load some kernel modules (see module loading messages above).

• When trying to load virtio module in KVM Slave node there is an error:

  # modprobe virtio
  modprobe: FATAL: Module virtio not found.

Cause

This means that virtio kernel modules are not available in custom kernel.

There is a corresponding RHEL bug for reference.

Resolution

1. Reboot the KVM node into the kernel provided by OS vendor
2. Access the node via SSH 
3. Load the necessary modules:

   # modprobe virtio
   # modprobe virtio_balloon
   # modprobe virtio_console
   # modprobe virtio_scsi
   # modprobe virtio_net
   # modprobe virtio_pci
   # modprobe virtio_ring

4. Get the current kernel version:

   # uname -r
   3.10.0-1062.18.1.el7.x86_64

5. Rebuild libguestfs appliance using the kernel version from previous step:

   # export SUPERMIN_KERNEL=/boot/vmlinuz-3.10.0-1062.18.1.el7.x86_64
   # export SUPERMIN_MODULES=/lib/modules/3.10.0-1062.18.1.el7.x86_64
   # export SUPERMIN_KERNEL_VERSION=3.10.0-1062.18.1.el7.x86_64
   # rm -rf /var/tmp/.guestfs-*
   # libguestfs-test-tool