VirtualBox is running out of virtual disk space. Default is 10gb. Want to expand, the graphical interface did not find an actionable menu. Google solved it with VBoxManage, the command tool that comes with Vbox.

C:\Program Files\Oracle\VirtualBox> VBoxManage modifyhd e:\ Vbox \Ubuntu12.04\ ubuntu1204-201302-disk1.vmdk –resize 30000
0%…
Progress state: VBOX_E_NOT_SUPPORTED
VBoxManage.exe: error: Resize hard disk operation for this format is not implemented yet!

the original virtual machine used VMDK format, this command can only support vdi format.

found that you can use VBoxManager to convert virtual hard disk storage file format
C:\Program Files\Oracle\VirtualBox> VBoxManage clonehd e:\ Vbox \Ubuntu12.04\ ubuntu1204-201302-disk1.vmdk e:\ Vbox \ ubuntu1204-201310-disk1.vdi –format vdi
0%… 10%… 20%… 30%… 40%… 50%… 60%… 70%… 80%… 90%… Clone hard disk created in format ‘VDI’. UUID: 455b7aa4-d776-8353-d9b5b3fa1
09b

C:\Program Files\Oracle\VirtualBox> Clone hard disk created in format ‘VDI’. VBoxManage modifyhd e:\ Vbox \Ubuntu12.04\Ubunt
u1204-201310-disk1.vdi –resize 30000
0%… 10%… 20%… 30%… 40%… 50%… 60%… 70%… 80%… 90%… 100%
No more reporting that mistake.
This article from: http://blog.sina.com.cn/s/blog_484d87770101olzr.html