14 Known limitations • On Mac OS X hosts, the following features are not yet implemented: – Numlock emulation – CPU frequency metric – Memory ballooning • Mac OS X Server guests: – Mac OS X Server guests can only run on a certain host hardware. For details about li- cense and host hardware limitations, please see chapter 3.1.1, Mac OS X Server guests, page 40. – VirtualBox does not provide Guest Additions for Mac OS X Server at this time. – The graphics resolution currently defaults to 1024x768 as Mac OS X Server falls back to the built-in EFI display support. See chapter 3.12.1, Video modes in EFI, page 52 for more information on how to change EFI video modes. – Even when idle, Mac OS X Server guests currently burn 100% CPU. This is a power management issue that will be addressed in a future release. – Mac OS X Server guests only work with one CPU assigned to the VM. Support for SMP will be provided in a future release. – Depending on your system and version of Mac OS X Server, you might experience guest hangs after some time. This can be fixed by turning off energy saving (set timeout to “Never”) in the system preferences. – By default, the VirtualBox EFI enables debug output of the Mac OS X Server kernel to help you diagnose boot problems. Note that there is a lot of output and not all errors are fatal (they would also show on your physical Mac). You can turn off these messages by issuing this command: VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" " " To revert to the previous behavior, use: VBoxManage setextradata "VM name" "VBoxInternal2/EfiBootArgs" "" • Solaris hosts: – There is no support for USB devices connected to Solaris 10 hosts. – USB support on Solaris hosts requires kernel version snv_124 or higher. Webcams and other isochronous devices are known to have poor performance. – No ACPI information (battery status, power source) is reported to the guest. – No support for using wireless adapters with bridged networking. • Guest Additions for OS/2. Shared folders are not yet supported with OS/2 guests. In ad- dition, seamless windows and automatic guest resizing will probably never be implemented due to inherent limitations of the OS/2 graphics system. 182