SolusVM KVM VPS creation fails: no bootable device: appliance closed the connection unexpectedly, see earlier error messages

Symptoms 

• VPS creation fail. VPS is online but there is the error in VNC console:

  CONFIG_TEXT: No bootable device

• libguestfs-test-tool fails with error:

  CONFIG_TEXT: libguestfs: error: appliance closed the connection unexpectedly, see earlier error messages
  libguestfs: child_cleanup: 0x55a44e3416f0: child process died
  libguestfs: error: guestfs_launch failed, see earlier error messages

  Or

  CONFIG_TEXT: Google, Inc.
  Serial Graphics Adapter 06/09/14
  SGABIOS $Id: sgabios.S 8 2010-04-22 00:03:40Z nlaredo $ (mockbuild@) Mon Jun 9 21:33:48 UTC 2014
  Term: 80x24
  4 0
  SeaBIOS (version 1.11.0-2.el7)
  Machine UUID 7775039b-2ced-4400-a284-b7ca5fde3cde
  Alarm clock

Cause

Default qemu wrapper does not work.

Resolution

1. Connect to KVM Slave node via SSH
2. Set the default qemu wrapper as 'tcg':

   # LIBGUESTFS_BACKEND_SETTINGS=force_tcg
   # export LIBGUESTFS_BACKEND_SETTINGS

3. Execute the following command:

   # touch /usr/local/solusvm/data/.LIBGUESTFS_BACKEND_SETTINGS_FORCE_TCG