Virtualbox

Installation on Ubuntu

http://www.ubuntugeek.com/virtualbox-4-3-8-released-and-ubuntu-installation-instructions-included.html

Virtualization in the host machine

Note that even the host machine is 64-bit, if the vT is not available/enabled in the BIOS, we cannot install 64-bit OS in the guest machine.

Virtual box guest addition

Install guest addition for virtualbox on Debian See the link [1]

virtual machine software benchmark

• http://dl.maximumpc.com/Archives/MPC%202012%2007-web.pdf

Trouble Shooting

the headers of the current running kernel were not found

sudo apt-get install dkms build-essential linux-headers-$(uname -r)

virtualbox failed to create the host-only network

Virtualbox (*.deb) was downloaded from virtualbox website. However, when I want to create a host-only network, I have to execute

sudo /etc/init.d/vboxdrv setup
sudo apt-get install dkms build-essential linux-headers-$(uname -r)

This also solves the error "Kernel driver not installed (rc=-1908)".

Ubuntu 14.10

• http://askubuntu.com/questions/541006/ubuntu-14-10-does-not-install-in-virtualbox

Especially, if my host is already Ubuntu, I want to use RightCtrl + F1 and RightCtrl + F7 to switch between the terminal and the graphical desktop. If my host is Windows OS, I can use Ctrl + Alt + F1 and Ctrl + Alt + F7 to switch.

Use VirtualBox

Different networks

See diagrams on https://blogs.oracle.com/fatbloke/entry/networking_in_virtualbox1

1. NAT
2. Bridge
3. Host Only: Host can access guest, but not the other direction. Outside cannot access guests. Good for running a test web server.
4. Internal Network: Guests can access each other but host still cannot access guests. This is good for testing when you need a separate, clean network, and you can create sophisticated internal networks with vm's that provide their own services to the internal network. (e.g. Active Directory, DHCP, etc).

Share folders

Suppose we want to share some folder from host to guest. Assume in Virtualbox, we use "Downloads" as the folder name in Share Folders dialog.

Method 1: Use Auto-mount option built in VirtualBox. But I get a permission denied error. The reason is we have to add the current user to the group vboxsf.

sudo usermod -a -G vboxsf USERNAME
# reboot is required
# the shared folder is under /media/ with sf_ as prefix.

See http://www.cyberciti.biz/faq/howto-linux-add-user-to-group/ for more examples of using usermod command.

Howtogeek.com provides another way to add user to vboxsf.

sudo adduser USERNAME vboxsf

We can then use id USERNAME to verify you are in the vboxsf group.

Method 2: We can use the following method to get an access to Downloads folder for this session only. See also howtogeek.com.

sudo mkdir /mnt/Downloads
sudo mount -t vboxsf Downloads /media/downloads

Method 3: We can use the following method for permanent solution.

sudo nano /etc/fstab
sudo mkdir /mnt/Downloads
# Add a new line
# Downloads /mnt/Downloads/ vboxsf defaults 0  0  
sudo mount -a

PS: There is a bug in virtualbox 4.3.10 which results an error

mount: wrong fs type, bad option, bad superblock on hostshare,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail or so

The solution is to run

sudo rm /sbin/mount.vboxsf
sudo ln -sf /usrs/lib/x86_64-linux-gnu/VBoxGuestAdditions/mount.vboxsf /sbin/mount.vboxsf

Seamless mode

If we want to run the app from guest machine on host machine (to hide the guest machine desktop) so the app looks like from the host machine, we can head to View->Switch to Seamless Mode in VirtualBox.

Snapshots

If we are installing a sketchy program, we can take a snapshot, install the program, then revert to your snapshot if things go wrong.

http://www.howtogeek.com/150258/how-to-save-time-by-using-snapshots-in-virtualbox/

1. Create a clean machine.
2. There are two ways:
   • (When the VM is off) Switch from 'Details' to 'Snapshots' on the right-hand side of the VB window. Right click 'Current State' and click 'Create Snapshot'.
   • (When the VM is on) Machine > Take a snapshot. Give it an intuitive name and description. Shutdown the current machine (This seems to be a good practice every time after we create a VM).
3. Select the Virtual machine from the list and switch over to the snapshots view (top-right corner). Right click a snapshot and choose 'Restore snapshot'. Uncheck the option of 'Create a snapshot of the current machine state'. Click 'Restore'.
4. You should see the "Current State(changed)" will become "Current State" the same as the snapshot you selected to restore to.

Port forward

If you’d like to run server software inside a virtual machine, you’ll probably want to set up port forwarding so the server software is reachable from outside of the virtual machine. You’ll find this option in the Network settings pane, under Advanced.

If we change to use the 'Bridged' network, we don't need to use port forward. We use 'port forward' if we use the default 'NAT' network.

http://www.howtogeek.com/122641/how-to-forward-ports-to-a-virtual-machine-and-use-it-as-a-server/

Increase the guest machine space

• http://www.dedoimedo.com/computers/virtualbox-shrink-expand-disks.html
• http://www.howtogeek.com/124622/how-to-enlarge-a-virtual-machines-disk-in-virtualbox-or-vmware/

Boot virtual machines from USB drives

http://www.howtogeek.com/187721/how-to-boot-from-a-usb-drive-in-virtualbox/

Clone vs Import/Export appliance

Clone will create a new VM directory (including *.vdi) on the same machine.

Import/Export appliance (*.ova) allows to transport the appliance to a new machine.

1. The appliance will not be touched on the new machine.
2. The storage space cannot be adjust when we import an appliance.
3. The .ova file can be opened in VMware Play.

Manage virtual machines

Headless VirtualBox with phpvirtualbox

http://www.howtoforge.com/managing-a-headless-virtualbox-installation-with-phpvirtualbox-ubuntu-12.04

For some reason, I got an error 'Could not connect to host (127.0.0.1:18083)'. A solution is to restart it. See this wiki from sourceforget.net.

sudo /etc/init.d/vboxweb-service stop
sudo /etc/init.d/vboxweb-service start

Other visualization software

Hypervisor/Virtual machine monitor

Hypervisor from wikipedia.

VMware

apt-get update
apt-get install build-essential module-assistant
m-a prepare
cd Downloads
tar xzvf /media/cdrom0/VMwareTools-9.2.0-799703.tar.gz
cd vmware-tools-distrib
./vmware-install.pl
[Accept all default]
shutdown -r now

Convert between vmdk and ova format

• ova
• vmdk

See this article in howtogeek.com

vSphere

This is a type 1 hypervisor.

Emulation vs virtualization

Virtualization allows users to configure virtual machines outfitted with similar hardware and processors as the host system, whereas emulation simulates different hardware and processor configurations in software.

Emulators are what allow you to run old Commodore 64 or NES games on a PC, for example.