8 VBoxManage • The setlinkstate1-N operation connects or disconnects virtual network cables from their network interfaces. • nic1-N null|nat|bridged|intnet|hostonly: 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 connected to the host (null), use network address translation (nat), bridged net- working (bridged) or communicate with other virtual machines using internal network- ing (intnet) or host-only networking (hostonly). These options correspond to the modes which are described in detail in chapter 6.2, Introduction to networking modes, page 84. • usbattach and usbdettach make host USB devices visible to the virtual machine on the fly, without the need for creating filters first. The USB devices can be specified by UUID (unique identifier) or by address on the host system. You can use VBoxManage list usbhost to locate this information. • vrde on|off lets you enable or disable the VRDE server, if it is installed. • vrdeport default|ports changes the port or a range of ports that the VRDE server can bind to “default” or “0” means port 3389, the standard port for RDP. For details, see the description for the --vrdeport option in chapter 8.7.3, Serial port, audio, clipboard, remote desktop and USB settings, page 113. • setvideomodehint requests that the guest system change to a particular video mode. This requires that the Guest Additions be installed, and will not work for all guest systems. • The setcredentials operation is used for remote logons in Windows guests. For details, please refer to chapter 9.2, Automated guest logons, page 136. • The guestmemoryballoon operation changes the 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. This must be specified in megabytes. For details, see chapter 4.8.1, Memory ballooning, page 69. • The cpuexecutioncap 1-100: This operation controls how much cpu time a virtual CPU can use. A value of 50 implies a single virtual CPU can use up to 50% of a single host CPU. 8.12 VBoxManage discardstate This command discards the saved state of a virtual machine which is not currently running, which will cause its operating system to restart next time you start it. This is the equivalent of pulling out the power cable on a physical machine, and should be avoided if possible. 8.13 VBoxManage adoptstate If you have a saved state file (.sav) that is seperate from the VM configuration, you can use this command to “adopt” the file. This will change the VM to saved state and when you start it, VirtualBox will attempt to restore it from the saved state file you indicated. This command should only be used in special setups. 118