==== VirtualBox running CentOS 6 Notes ====

[[https://www.virtualbox.org/]]

[[http://www.if-not-true-then-false.com/2010/install-virtualbox-guest-additions-on-fedora-centos-red-hat-rhel/comment-page-7/|Other Tips for VBox Guest Additions on Fedora 22/21, CentOS/RHEL 7.1/6.7/5.11]]


Follow the provided installation instructions in the manual.

**Note:**  Just because the host machine is 64-bit does not mean the VirtualBox will run a guest 64-bit machine.  Processor limits of the host machine seem to be the culprit or certain manufacturer's chips seem to be the limit.

[[virtualbox_general_notes|Guest Additions in Run Level 3 - see VirtualBox General Notes]]

**December 2015:**

Machine took power hit and UPS failed.  VirtualBox application would start, but no virtual machines would start.  Kernel error.  Had to remove VirtualBox and reinstall the same version (VirtualBox-5.0-5.0.10_104061_el6-1.x86_64.rpm)


**November 2015:\\ 1) Building the OpenGL support module [ FAILED ] **
  * cd /media/VBOXADDITIONS_5.0.10_104061
  * export MAKE=’/usr/bin/gmake -i’ [[http://www.jianshu.com/p/863bea519106|(See online info)]]
  * sh VBoxLinuxAdditions.run

**July 2015:\\ 1) VirtualBox 5.0 mini toolbar does not work correctly in full screen**
  * See https://www.virtualbox.org/ticket/14257
  * Source RPM is VirtualBox-5.0-5.0.0_101573_el6-1.x86_64.rpm

**February 2014:\\ 1) Boot error message: (modprobe vboxdrv failed. Please use 'dmesg' to find out why)**

Install the dkms rpm package.  It can slow the time to perform updates but it will stop this error message and also allow VirtualBox to work with new kernels seamlessly.


**December 2013:\\ 1) Upgrading to VirtualBox-4.3-4.3.4_91027_el6-1.x86_64.rpm causes failures when trying to start the VMs**

Need to go into BIOS and under security options allow VirtualMachines to run.

**2) Error message: \\
Building the OpenGL support module                         [FAILED]**

Follow workaround on https://forums.oracle.com/message/11282251 or https://forums.virtualbox.org/viewtopic.php?f=3&t=58855

<code>
# cd /usr/src/kernels/2.6.32-431.el6.i686/include/drm/ 
# ln -s /usr/include/drm/drm.h drm.h 
# ln -s /usr/include/drm/drm_sarea.h drm_sarea.h 
# ln -s /usr/include/drm/drm_mode.h drm_mode.h 
# ln -s /usr/include/drm/drm_fourcc.h drm_fourcc.h
</code>

**April 2013:\\ OpenGL support fails when installing Guest Additions on VirtualBox 4.2.10 r84104** \\

Mount the Guest Additions CD .iso (Devices> Install Guest Additions...)

Open terminal as root:
<code>
# export MAKE='/usr/bin/gmake -i'
# cd /media/VBOXADDITIONS_4.2.10_84104
# sh VBoxLinuxAdditions.run
</code>


[[https://forums.virtualbox.org/viewtopic.php?f=3&t=42424]]

**March 2013:\\ No X Display CENTOS 6.4** \\
Need to investigate.  Problem exists with VirtualBox 4.2.8 r83876

[[http://wiki.centos.org/Manuals/ReleaseNotes/CentOS6.4#head-a39645d5503daf52829401f298c60712af070009]]

[[https://www.centos.org/modules/newbb/viewtopic.php?viewmode=flat&order=ASC&topic_id=41802&forum=55&move=prev&topic_time=1362817803]]

[[https://www.centos.org/modules/newbb/viewtopic.php?topic_id=41693&forum=55]]

Appears that removing /etc/X11/xorg.conf (save to a backup file) and letting the system rebuild xorg.conf allows VirtualBox to come again into graphical X Windows.



**August 2012:\\ Crashes and won't boot** \\
Crashes immediately upon boot on Dell E510 hardware.  Add "edd=off" to kernel boot parameter.


**July 2012:\\ Crashes and won't boot** \\
Chipset problems cropped up for later kernels in Centos6.2...kernel panic upon booting.  Fix is:

Change chipset settings in the VirtualBox Manager from PIIX3 to ICH9.  Turn on IO APIC.  Reboot guest CentOS.  \\
https://forums.virtualbox.org/viewtopic.php?f=3&t=49007

The default settings under System > Motherboard was Chipset PIIX3, unchecked enable IO APIC

Other notes:

To migrate a VM install from other piece of hardware, just rsync ~/.VirtualBox and the location of the Virtual Box machine (default is ~/VirtualBox VMs)

When updating kernel on VM, you need to re-install guest additions and restart guest OS to get the seamless view/auto resize mode again.

Network: \\
http://www.dedoimedo.com/computers/virtualbox-network-sharing.html

Screen resolution: \\
http://ubuntuforums.org/showthread.php?t=691495 \\
http://ubuntuforums.org/showthread.php?p=5145028#post5145028



Install the "VirtualBox Guest Additions" add-on to the Virtual Box Manager.  Then login to the guest system and double-click the desktop icon for Additions.  This package will enable proper screen resolution, mouse behavior, etc.

Change the guest OS to a higher display resolution and maximize the guest VM display window

Change theme if desired (under System > Preferences > Appearance > Themes)

Change mouse pointer to white (under System > Preferences > Appearance > Themes > Customize)

Change the system fonts to 8 point (System > Preferences > Appearance > Themes) and under the Advanced tab change the DPI resolution from the default (98) to 96.

Set up .bashrc

Set up gnome-terminal to monospace 9pt, unlimited text scrollback, blinking cursor if available

If desired, install webcore-fonts-1.3-1 (and see if Monospace 9pt fonts looks any different)

Adobe Reader is not installed in default channel - see CentOS Additional resource page at [[http://wiki.centos.org/AdditionalResources/Repositories]] and look for the Adobe Repository
  * I just got Adobe Acrobat Reader 64 bit for Red Hat Enterprise Linux 6 working, and it wasn't too easy. First, I downloaded a binary from http://get.adobe.com/reader/. I made it executable and ran it, but the program wouldn't launch. Using 'strace -e open acroread', I could see it was trying to open a libxml2.so.2, but it wasn't seeing the one on my system under /usr/lib64. Doing a 'yum list libxml2\*', I could see there was also a libxml2.i686 that wasn't installed yet. After doing 'yum install libxml2.i686', the program started up a little further, but then complained about an missing library. More searching led me to do 'yum install gtk2-2.18.9-4.el6.i686'. At last, the Adobe Acrobat Reader 9.4 ran successfully. (from [[http://wrightrocket.blogspot.com/2011/01/adobe-acrobat-reader-x-64-bit-for-red.html#!/2011/01/adobe-acrobat-reader-x-64-bit-for-red.html Wrightrocket blog]]

Install Adobe flash (download rpm from Adobe website)

Install work's VPN software.  Likely need to do a 'yum install libxml2.i686' first, though.

KRDC on CentOS6 guest OS: the width needs to be about 6 pixels less than current screen resolution to avoid the end scrollbars.  Be sure to use FQDN.

KRDC on CentOS5 host OS: works fine; appears to make rdp:/hostname.domain.com by default a VNC connection which doesn't have odd black cursor/mouse.

Issues with CentOS6 installed under VirtualBox:
  * kernel updates require Virtual Box's Guest Additions to be re-installed
    * Inside the guest OS, go to the hovering menu bar and select Devices > Install Guest Additions
    * Click on the icon that appears on the desktop (CD-ROM)
    * After the additions are installed, reboot the Guest OS, login
    * The guest additions behavior and fullscreen mode should work normally again
  * mouse cursor odd - 'hand' is black and not white
    * change mouse theme on guest OS as stated above
  * mouse cursor when connecting via krdc is ugly black
    * use rdesktop instead; see wiki entry on remote desktop connections
  * network connection is not initially established upon boot
     * right-click network icon to disable/enable
     * right-click and select System eth0 to start the networking
  * network connection is not part of the LAN (need to establish a route?)
  * Firefox is v3.x by default, follow this page to update to v9.x
     * Note that v9.x has funny behavior with icons at top of page; perhaps remove .mozilla from user home directory to reset
     * http://www.if-not-true-then-false.com/2011/install-firefox-on-fedora-centos-red-hat-rhel/
     * libstdc++.so.6 error: check rpmfind.net for open64-5.0-0.x86_64.rpm (didn't seem to work; backed out of it)
     * yum install libstdc++.i686
     * yum install xulrunner
     * may need to install the i686 package versions because Firefox is likely still 32bit
     * also did a yum install * 
  * How to install Firefox 10 (not tested)
    * [[http://www.if-not-true-then-false.com/2011/install-firefox-on-fedora-centos-red-hat-rhel/]]
  * How to install adobe flash 11 (not tested)
    * [[http://www.if-not-true-then-false.com/2010/install-adobe-flash-player-10-on-fedora-centos-red-hat-rhel/]]
  * How to install Java 7 (not tested)
    * [[http://www.if-not-true-then-false.com/2010/install-sun-oracle-java-jdk-jre-7-on-fedora-centos-red-hat-rhel/]]
  * How to install Thunderbird (not tested)
    * [[http://www.if-not-true-then-false.com/2011/install-thunderbird-on-fedora-centos-and-red-hat-rhel/]]
  * Screen keeps blanking, try this: http://www.nvnews.net/vbulletin/showthread.php?t=72051
     * xset -dpms in your ~/.xsession or ~/.xinitrc file
     * xset -dpms s off

Old note for after new kernel install.....do this as root:

/etc/init.d/vboxdrv setup

Possible tests:
  * A clean install of CentOS6 on a separate hard disk in a desktop PC
  * A guest install of CentOS5 with VirtualBox
  * Performance is marginally adequate on a modern 64-bit Windows host OS with 4GB DDR3 RAM