I've installed the 4.2 Beta1, created a Windows 7 VM installed Win7 and made a shutdown to later changed the settings. I've increases the guest RAM to 3GB and now the VM crashes at boot with a GURU_MEDITATION. The confusing part is the reason for the crash:
So why can't a start a VM if there are 12GB RAM free?VirtualBox VM 4.2.0_BETA1 r79756 win.amd64 (Aug 3 2012 15:16:20) release log
00:00:01.373562 Log opened 2012-08-10T11:26:11.390625000Z
00:00:01.373578 OS Product: Windows 7
00:00:01.373588 OS Release: 6.1.7601
00:00:01.373592 OS Service Pack: 1
00:00:01.373615 Host RAM: 16383MB RAM, available: 12794MB
00:00:14.468339 PGM: Failed to procure handy pages; rc=VERR_NO_MEMORY rcAlloc=VINF_SUCCESS rcSeed=VINF_SUCCESS cHandyPages=0x8
00:00:14.468350 cAllPages=0xd044c cPrivatePages=0xc81f8 cSharedPages=0x0 cZeroPages=0x822a
00:00:14.468383 GMM: Statistics:
00:00:14.468383 Allocated pages: b7dfc
00:00:14.468386 Maximum pages: c009e
00:00:14.468387 Ballooned pages: 0
00:00:14.468426 PGM: Failed to procure handy pages; rc=VERR_NO_MEMORY rcAlloc=VINF_SUCCESS rcSeed=VINF_SUCCESS cHandyPages=0x7
00:00:14.468428 cAllPages=0xd044c cPrivatePages=0xc81f9 cSharedPages=0x0 cZeroPages=0x8229
00:00:14.468436 GMM: Statistics:
00:00:14.468436 Allocated pages: b7dfc
00:00:14.468437 Maximum pages: c009e
00:00:14.468438 Ballooned pages: 0
00:00:14.468454 VM: Raising runtime error 'HostMemoryLow' (fFlags=0x2)
00:00:14.468465 PGM: Failed to procure handy pages; rc=VERR_NO_MEMORY rcAlloc=VINF_SUCCESS rcSeed=VINF_SUCCESS cHandyPages=0x7
00:00:14.468471 cAllPages=0xd044c cPrivatePages=0xc81f9 cSharedPages=0x0 cZeroPages=0x8229
00:00:14.468502 GMM: Statistics:
00:00:14.468502 Allocated pages: b7dfc
00:00:14.468503 Maximum pages: c009e
00:00:14.468504 Ballooned pages: 0
00:00:14.468513 VM: Raising runtime error 'HostMemoryLow' (fFlags=0x2)
00:00:14.468517 AssertLogRel E:\tinderbox\win-rel\src\VBox\VMM\VMMR3\VMM.cpp(1707) int __cdecl VMMR3EmtRendezvous(struct VM *,unsigned int,int (__cdecl *)(struct VM *,struct VMCPU *,void *),void *): !pVCpu->vmm.s.fInRendezvous
00:00:14.468530 Console: VM runtime error: fatal=false, errorID=HostMemoryLow message="Unable to allocate and lock memory. The virtual machine will be paused. Please close applications to free up memory or close the VM"
00:00:14.468641 Changing the VM state from 'RUNNING' to 'GURU_MEDITATION'.
00:00:14.468821 VMR3Suspend:
00:00:14.468851 RUNNING -> SUSPENDING, RUNNING_LS -> SUSPENDING_EXT_LS failed, because the VM state is actually GURU_MEDITATION
00:00:14.468865 VMSetError: E:\tinderbox\win-rel\src\VBox\VMM\VMMR3\VM.cpp(3491) int __cdecl vmR3TrySetState(struct VM *,const char *,unsigned int,...); rc=VERR_VM_INVALID_VM_STATE
00:00:14.526292 VMSetError: VMR3Suspend failed because the current VM state, GURU_MEDITATION, was not found in the state transition table
00:00:14.526338 Console: VM runtime error: fatal=false, errorID=HostMemoryLow message="Unable to allocate and lock memory. The virtual machine will be paused. Please close applications to free up memory or close the VM"