It is sometimes convenient to be able to run Tails without having to restart your computer every time. This is possible using virtual machines.
With virtual machines, it is possible to run Tails inside a host operating system (Linux, Windows, or Mac OS X). A virtual machine emulates a real computer and its operating system, called guest which appears in a window on the host operating system.
When running Tails in a virtual machine, you can use most features of Tails from your usual operating system and use both in parallel without the need to restart the computer.
This is how Tails looks like when run in a virtual machine on Debian using VirtualBox:

We do not currently provide a solution for running a virtual machine inside a Tails host. See ticket #5606.
Security considerations
Both the host operating system and the virtualization software are able to monitor what you are doing in Tails.
If the host operating system is compromised with a software keylogger or other malware, then it can break the security features of Tails.
Only run Tails in a virtual machine if both the host operating system and the virtualization software are trustworthy.
Traces of your Tails session are likely to be left on the local hard disk. For example, host operating systems usually use swapping (or paging) which copies part of the RAM to the hard disk.
Only run Tails in a virtual machine if leaving traces on the hard disk is not a concern for you.
This is why Tails warns you when it is running inside a virtual machine.
Virtualization solutions
To run Tails inside a virtual machine, you need to have virtualization software installed on the host operating system. Different virtualization software exist for Linux, Windows, and Mac OS X.
The following list includes only free software as we believe that this is a necessary condition for it to be trustworthy. See the previous warning and our statement about free software and public scrutiny.
Proprietary virtualization software solutions exist such as VMWare but are not listed here on purpose.
VirtualBox is available for Linux, Windows, and Mac. Its free software version does not include support for USB devices and does not allow to use a persistent volume.
GNOME Boxes is available for Linux. It has a simple user interface but does not allow to use a persistent volume.
virt-manager is available for Linux. It has a more complex user interface and allows to use a persistent volume, either by:
- Starting Tails from a USB stick or SD card.
- Creating a virtual USB storage volume saved as a single file on the host operating system.
