For databases using bare metal and virtual machine infrastructure, Oracle Cloud Infrastructure uses per-second billing. This means that OCPU and storage usage is billed by the second, with a minimum usage period of 1 minute for Virtual Machine DB Systems and 1 hour for Bare Metal DB Systems.
Host-only networking can be thought of as a hybrid between the bridged and internal networking modes. As with bridged networking, the virtual machines can talk to each other and the host as if they were connected through a physical Ethernet switch. As with internal networking, a physical networking interface need not be present, and the virtual machines cannot talk to the world outside the host since they are not connected to a physical networking interface.
Virtual machine software is only the beginning
When host-only networking is used, Oracle VM VirtualBox creates a new software interface on the host which then appears next to your existing network interfaces. In other words, whereas with bridged networking an existing physical interface is used to attach virtual machines to, with host-only networking a new loopback interface is created on the host. And whereas with internal networking, the traffic between the virtual machines cannot be seen, the traffic on the loopback interface on the host can be intercepted.
Host-only networking is particularly useful for preconfigured virtual appliances, where multiple virtual machines are shipped together and designed to cooperate. For example, one virtual machine may contain a web server and a second one a database, and since they are intended to talk to each other, the appliance can instruct Oracle VM VirtualBox to set up a host-only network for the two. A second, bridged, network would then connect the web server to the outside world to serve data to, but the outside world cannot connect to the database.
VirtualBox is a hypervisor used to run operating systems in a special environment, called a virtual machine, on top of the existing operating system. VirtualBox is in constant development and new features are implemented continuously. It comes with a Qt GUI interface, as well as headless and SDL command-line tools for managing and running virtual machines.
It is also recommended to install the virtualbox-guest-iso package on the host running VirtualBox. This package will act as a disc image that can be used to install the guest additions onto guest systems other than Arch Linux. The .iso file will be located at /usr/lib/virtualbox/additions/VBoxGuestAdditions.iso, and may have to be mounted manually inside the virtual machine. Once mounted, you can run the guest additions installer inside the guest.
In order to avoid having to install the guest system manually, some operating systems support unattended installation. This allows the user to configure the system to be installed in VirtualBox's interface prior to starting the machine. At the end of the setup process, the operating system is installed without requiring any further user interaction. This feature requires the virtualbox-unattended-templatesAUR package.
The Oracle Extension Pack provides additional features and is released under a non-free license only available for personal use. To install it, the virtualbox-ext-oracleAUR package is available, and a prebuilt version can be found in the seblu repository.
If you are running out of space due to the small hard drive size you selected when you created your virtual machine, the solution adviced by the VirtualBox manual is to use VBoxManage modifyhd. However this command only works for VDI and VHD disks and only for the dynamically allocated variants. If you want to resize a fixed size virtual disk disk too, read on this trick which works either for a Windows or UNIX-like virtual machine.
If you think that editing a simple XML file is more convenient than playing with the GUI or with VBoxManage and you want to replace (or add) a virtual disk to your virtual machine, in the .vbox configuration file corresponding to your virtual machine, simply replace the GUID, the file location and the format to your needs:
The information about path to harddisks and the snapshots is stored between .... tags in the file with the .vbox extension. You can edit them manually or use this script where you will need change only the path or use defaults, assumed that .vbox is in the same directory with a virtual harddisk and the snapshots folder. It will print out new configuration to stdout.
UUIDs are widely used by VirtualBox. Each virtual machines and each virtual disk of a virtual machine must have a different UUID. When you launch a virtual machine in VirtualBox, VirtualBox will keep track of all UUIDs of your virtual machine instance. See the VBoxManage list to list the items registered with VirtualBox.
If you cloned a virtual disk manually by copying the virtual disk file, you will need to assign a new UUID to the cloned virtual drive if you want to use the disk in the same virtual machine or even in another (if that one has already been opened, and thus registered, with VirtualBox).
If you plan to use your virtual machine on another hypervisor or want to import in VirtualBox a virtual machine created with another hypervisor, you might be interested in reading the following steps.
Guest additions are available in most hypervisor solutions: VirtualBox comes with the Guest Additions, VMware with the VMware Tools, Parallels with the Parallels Tools, etc. These additional components are designed to be installed inside a virtual machine after the guest operating system has been installed. They consist of device drivers and system applications that optimize the guest operating system for better performance and usability by providing these features.
If you have installed the additions to your virtual machine, please uninstall them first. Your guest, especially if it is using an OS from the Windows family, might behave weirdly, crash or even might not boot at all if you are still using the specific drivers in another hypervisor.
Some companies provide tools which offer the ability to create virtual machines from a Windows or GNU/Linux operating system located either in a virtual machine or even in a native installation. With such a product, you do not need to apply this and the following steps and can stop reading here.
Each hypervisor have their own virtual machine configuration file: .vbox for VirtualBox, .vmx for VMware, a config.pvs file located in the virtual machine bundle (.pvm file), etc. You will have thus to recreate a new virtual machine in your new destination hypervisor and specify its hardware configuration as close as possible as your initial virtual machine.
It can be useful to start virtual machines directly with a keyboard shortcut instead of using the VirtualBox interface (GUI or CLI). For that, you can simply define key bindings in .xbindkeysrc. Please refer to Xbindkeys for more details.
To communicate between the VirtualBox guest and host using ssh, the server port must be forwarded under Settings > Network. When connecting from the client/host, connect to the IP address of the client/host machine, as opposed to the connection of the other machine. This is because the connection will be made over a virtual adapter.
Recent versions of Virtualbox have support for accelerating OpenGL inside guests. This can be enabled with a simple checkbox in the machine's settings, right below where video ram is set, and installing the Virtualbox guest additions. However, most Windows games use Direct3D (part of DirectX), not OpenGL, and are thus not helped by this method. However, it is possible to gain accelerated Direct3D in your Windows guests by borrowing the d3d libraries from Wine, which translate d3d calls into OpenGL, which is then accelerated. These libraries are now part of Virtualbox guest additions software.
If you have a dual boot system between Arch Linux and another operating system, it can become tedious to switch back and forth if you need to work in both. You may also experience performance or compatibility issues when using a virtual machine, which can impact your ability to do certain tasks.
This guide will let you reuse, in a virtual machine, your native Arch Linux installation when you are running your second operating system. This way, you keep the ability to run each operating system natively, but have the option to run your Arch Linux installation inside a virtual machine.
Depending on your hard drive setup, device files representing your hard drives may appear differently when you will run your Arch Linux installation natively or in virtual machine. This problem occurs when using FakeRAID for example. The fake RAID device will be mapped in /dev/mapper/ when you run your GNU/Linux distribution natively, while the devices are still accessible separately. However, in your virtual machine, it can appear without any mapping in /dev/sdaX for example, because the drivers controlling the fake RAID in your host operating system (e.g. Windows) are abstracting the fake RAID device.
Now, we need to create a new virtual machine which will use a RAW disk as virtual drive, for that we will use a 1Kio VMDK file which will be mapped to a physical disk. Unfortunately, VirtualBox does not have this option in the GUI, so we will have to use the console and use an internal command of VBoxManage.
While you continue using the CLI, it is recommended to use the VirtualBox GUI, to personalise the virtual machine configuration. Indeed, you must specify its hardware configuration as close as possible as your native machine: turning on the 3D acceleration, increasing video memory, setting the network interface, etc.
Finally, you may want to seamlessly integrate your Arch Linux with your host operating system and allow copy pasting between both OSes. Please refer to VirtualBox/Install Arch Linux as a guest#Install the Guest Additions for that, since this Arch Linux virtual machine is basically an Arch Linux guest.
If you want to migrate an existing native Windows installation to a virtual machine which will be used with VirtualBox on GNU/Linux, this use case is for you. This section only covers native Windows installation using the MSDOS/Intel partition scheme. Your Windows installation must reside on the first MBR partition for this operation to success. Operation for other partitions are available but have been untested (see #Known limitations for details). 2ff7e9595c
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