8 VBoxManage • You can influence the BIOS logo that is displayed when a virtual machine starts up with a number of settings. Per default, a VirtualBox logo is displayed. With --bioslogofadein on|off and --bioslogofadeout on|off, you can determine whether the logo should fade in and out, respectively. With --bioslogodisplaytime msec you can set how long the logo should be visible, in milliseconds. With --bioslogoimagepath imagepath you can, if you are so inclined, replace the image that is shown, with your own logo. The image must be an uncompressed 256 color BMP file. • --biosbootmenu disabled|menuonly|messageandmenu: This specifies whether the BIOS allows the user to select a temporary boot device. menuonly suppresses the message, but the user can still press F12 to select a temporary boot device. • --boot1-4 none|floppy|dvd|disk|net: This specifies the boot order for the virtual machine. There are four “slots”, which the VM will try to access from 1 to 4, and for each of which you can set a device that the VM should attempt to boot from. • --snapshotfolder default|path: This allows you to specify the folder in which snap- shots will be kept for a virtual machine. • --firmware efi|bios: Specifies which firmware is used to boot particular virtual ma- chine: EFI or BIOS. Use EFI only if your fully understand what you’re doing. • --guestmemoryballoon size sets the default size of the guest memory balloon, that is, memory allocated by the VirtualBox Guest Additions from the guest operating system and returned to the hypervisor for re-use by other virtual machines. size must be specified in megabytes. The default size is 0 megabytes. For details, see chapter 4.8.1, Memory ballooning, page 69. 8.7.2 Networking settings The following networking settings are available through VBoxManage modifyvm. With all these settings, the decimal number directly following the option name (“1-N” in the list below) specifies the virtual network adapter whose settings should be changed. • --nic1-N none|null|nat|bridged|intnet|hostonly|vde: With this, you can set, for each of the VM’s virtual network cards, what type of networking should be available. They can be not present (none), not connected to the host (null), use network address translation (nat), bridged networking (bridged) or communicate with other virtual ma- chines using internal networking (intnet), host-only networking (hostonly) or on Linux and FreeBSD hosts a Virtual Distributed Ethernet switch (vde). These options correspond to the modes which are described in detail in chapter 6.2, Introduction to networking modes, page 84. • --nictype1-N Am79C970A|Am79C973|82540EM|82543GC|82545EM|virtio: This al- lows you, for each of the VM’s virtual network cards, to specify which networking hardware VirtualBox presents to the guest see chapter 6.1, Virtual networking hardware, page 83. • --cableconnected1-N on|off: This allows you to temporarily disconnect a virtual network interface, as if a network cable had been pulled from a real network card. This might be useful for resetting certain software components in the VM. • With the “nictrace” options, you can optionally trace network traffic by dumping it to a file, for debugging purposes. 111