4 Guest Additions timestamp: 1229099826300088000, flags: Name: /VirtualBox/GuestInfo/Net/0/V4/Broadcast, value: 255.255.255.255, timestamp: 1229099826300220000, flags: Name: /VirtualBox/GuestInfo/Net/0/V4/Netmask, value: 255.255.255.0, timestamp: 1229099826300350000, flags: Name: /VirtualBox/GuestInfo/Net/0/Status, value: Up, timestamp: 1229099826300524000, flags: Name: /VirtualBox/GuestInfo/OS/LoggedInUsersList, value: username, timestamp: 1229099826317386000, flags: To query the value of a single property, use the “get” subcommand like this: $ VBoxManage guestproperty get "Windows Vista III" "/VirtualBox/GuestInfo/OS/Product" VirtualBox Command Line Management Interface Version 4.0.4 (C) 2005-2011 Oracle Corporation All rights reserved. Value: Windows Vista Business Edition To add or change guest properties from the guest, use the tool VBoxControl. This tool is included in the Guest Additions of VirtualBox 2.2 or later. When started from a Linux guest, this tool requires root privileges for security reasons: $ sudo VBoxControl guestproperty enumerate VirtualBox Guest Additions Command Line Management Interface Version 4.0.4 (C) 2009-2011 Oracle Corporation All rights reserved. Name: /VirtualBox/GuestInfo/OS/Release, value: 2.6.28-18-generic, timestamp: 1265813265835667000, flags: NULL Name: /VirtualBox/GuestInfo/OS/Version, value: #59-Ubuntu SMP Thu Jan 28 01:23:03 UTC 2010, timestamp: 1265813265836305000, flags: NULL ... For more complex needs, you can use the VirtualBox programming interfaces see chapter 11, VirtualBox programming interfaces, page 163. 4.7 Guest control Starting with version 3.2, the Guest Additions of VirtualBox allow starting applications inside a VM from the host system. For this to work, the application needs to be installed inside the guest no additional software needs to be installed on the host. Additionally, text mode output (to stdout and stderr) can be shown on the host for further processing along with options to specify user credentials and a timeout value (in milliseconds) to limit time the application is able to run. This feature can be used to automate deployment of software within the guest. Starting with version 4.0, the Guest Additions for Windows allow for automatic updating (only already installed Guest Additions 4.0 or later). Also, copying files from host to the guest as well as remotely creating guest directories is available. To use these features, use the VirtualBox command line, see chapter 8.29, VBoxManage guest- control, page 127. 4.8 Memory overcommitment In server environments with many VMs the Guest Additions can be used to share physical host memory between several VMs, reducing the total amount of memory in use by the VMs. If memory usage is the limiting factor and CPU resources are still available, this can help with packing more VMs on each host. 68