On Linux, makes use of a custom version of Mozilla XPCOM (cross platform component object model) for interprocess and intraprocess communication (IPC). The process VBoxSVC serves as a communication hub between different processes and maintains the global configuration, such as the XML database. When starting an component, the processes VBoxSVC and VBoxXPCOMIPCD are started automatically. They are only accessible from the user account they are running under. VBoxSVC owns the configuration database which normally resides in ~/.config/VirtualBox, or the appropriate configuration directory for your operating system. While it is running, the configuration files are locked. Communication between the various components and VBoxSVC is performed through a local domain socket residing in /tmp/.vbox-username-ipc. In case there are communication problems, such as an application cannot communicate with VBoxSVC, terminate the daemons and remove the local domain socket directory.