From 382a5f3f456598270154706f0e03b17a526f062f Mon Sep 17 00:00:00 2001
From: sergiomt <sergiom@knowgate.com>
Date: Tue, 16 Jul 2019 09:26:13 +0200
Subject: [PATCH] Add notes on 3D acceleration

---
 doc/TROUBLESHOOT.md | 15 +++++++++++++++
 doc/VBOX_CONFIG.md  | 19 +++++++++++++++++--
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/doc/TROUBLESHOOT.md b/doc/TROUBLESHOOT.md
index 239380a..6f62897 100644
--- a/doc/TROUBLESHOOT.md
+++ b/doc/TROUBLESHOOT.md
@@ -1,5 +1,7 @@
 # Troubleshooting
 
+## Vagrantfile
+
 In case you have made any change to Vagrantfile then validate it with:
 
 `vagrant validate`
@@ -17,3 +19,16 @@ For trying to stablish an SSH connection with debug enabled use:
 `vagrant ssh -- -vvv`
 
 At Vagrantfile, set `vb.gui = true` enable the GUI of VirtualBox and see whether the VM is waiting for input on startup
+
+## Grub
+
+In case you need to change grub configuration, for example to edit boot command line, do:
+
+`sudo vi /etc/default/grub`
+
+Change the properties as required and then execute
+
+`sudo grub2-mkconfig -o /boot/grub2/grub.cfg`
+
+`sudo grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg`
+
diff --git a/doc/VBOX_CONFIG.md b/doc/VBOX_CONFIG.md
index 69a88ba..488a129 100644
--- a/doc/VBOX_CONFIG.md
+++ b/doc/VBOX_CONFIG.md
@@ -4,9 +4,16 @@
 
 ## INSTALL VIRTUAL BOX GUEST ADDITIONS
 
-See [VirtualBox Guest Additions on CentOS 7.5](https://www.if-not-true-then-false.com/2010/install-virtualbox-guest-additions-on-fedora-centos-red-hat-rhel/).
+If your CentOS image does not include VirtualBox Guest Additions then download the version of Guest Additions that matches exactly your installed VirtualBox version from [here](http://download.virtualbox.org/virtualbox/) rename it to VBoxGuestAdditions.iso and place it in the same directory as Virtualbox.exe is which for Windows typically is C:\Program Files\VirtualBox.
 
-Execute:
+The easiest way to get VirtualBox Guest Additions is by mean of using the [vagrant-vbguest plugin](https://github.com/dotless-de/vagrant-vbguest).
+Just install the plugin before you do vagrant up
+
+`vagrant plugin install vagrant-vbguest`
+
+See also [VirtualBox Guest Additions on CentOS 7.5](https://www.if-not-true-then-false.com/2010/install-virtualbox-guest-additions-on-fedora-centos-red-hat-rhel/).
+
+To manully install or upgrade do:
 
 ```
 sudo yum install gcc kernel-devel kernel-headers dkms make bzip2 perl
@@ -16,6 +23,14 @@ cd /media/VirtualBoxGuestAdditions
 ./VBoxLinuxAdditions.run
 ```
 
+The kernel-headers and kernel-devel must match exactly the version of your installed kernel.
+In order to check this do:
+`uname -r` 
+and
+`rpm -q kernel-devel`
+If the versions don't match then `yum remove` kernel-devel and kernel-headers and `yum install`again with the exact version required.
+
+
 -------------------------------------------------------------------------------
 
 ## REBUILD THE BASE BOX