这个问题很多人遇到没解决，但其实是可以达到目的的，关键在于你的思路。还是先来看一下Virtual Box在修改硬盘大小时报的错吧。
www.linuxidc.com @ www.linuxidc.com :~$ VBoxManage modifyhd "/home/benq/VirtualBox VMs/WinXpWork01/WinXpWork01.vbox" --resize 30900
VBoxManage: error: Could not get the storage format of the medium '/home/benq/VirtualBox VMs/WinXpWork01/WinXpWork01.vbox' (VERR_NOT_SUPPORTED)
VBoxManage: error: Details: code VBOX_E_IPRT_ERROR (0x80bb0005), component Medium, interface IMedium, callee nsISupports
Context: "OpenMedium(Bstr(pszFilenameOrUuid).raw(), enmDevType, AccessMode_ReadWrite, fForceNewUuidOnOpen, pMedium.asOutParam())" at line 210 of file VBoxManageDisk.cpp
