Unable to allocate and lock memory

[mav7748]

I am running Oracle linux 64-bit guest on a Windows 7 64 bit. Whenever I allocate more than 4096MB RAM i get the following error. Can someone please help. I am running virtual box version 4.3.20. When i notice the windows task bar memory the free memory is almost 0 but it has plenty of avaliable memory. Not sure why the VM is not able to swap the cached memory and is only using the free memory.
Attached is the VM log file.

00:22:57.781867 AssertLogRel F:\tinderbox\win-4.3\src\VBox\VMM\VMMR3\VMM.cpp(1756) int __cdecl VMMR3EmtRendezvous(struct VM *,unsigned int,int (__cdecl *)(struct VM *,struct VMCPU *,void *),void *): !pVCpu->vmm.s.fInRendezvous
00:22:57.782357 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"
00:22:57.784090 Changing the VM state from 'RUNNING' to 'GURU_MEDITATION'

[mpack]

You are trying to allocate a 7GB chunk of host RAM, when the host only has a total of 9.2GB available. VirtualBox needs to allocate memory in one contiguous chunk. Failure means that some application has locked itself into the middle of your host RAM, and hence is blocking such large allocations. Solutions would involve finding out what the app is and how to move it in memory, or give less RAM to the VM.