Off you go! A story of moving out my devtest VM

This article is intended for people who like to play with their laptops at home, taking advantage of the CPU‘s virtualization capabilities therefore firing up several VMs. I assume everybody know by now what a VM is. The story is more compelling to those using a laptop with an internal SSD drive which (due to higher cost) has usually less usable storage capacity as opposed to the old school HDD. I like to keep a Windows-based VM around to test random stuff from time to time or even use some specific tools which either don’t have yet a good Unix/Linux alternative or just because I’m too lazy. My Hypervisor of choice is Oracle’s VirtualBox due to its simplicity and user friendliness. My Windows 7 VM (more specifically the virtual disk used by it a.k.a. “W7_SystemDisk.vdi” file) has recently grown to 30 GiB which is a lot for my limited SSD capacity. Therefore, I decided that I must do something about it. My decision was grounded on the fact that I rarely use this VM (like once a week) and I have more important ones to build and run (i.e. try new Linux distribution releases). Given that my laptop has a built-in SD slot, I went and bought a Samsung micro SDXC card to use it as a new home for my afore-mentioned VM.

Samsung Pro 64

Of course one can use a standard USB flash drive for the very same purpose. Next important choice I had to decide upon was of course: which file system to use? There is always a trade-off between usability (portability) and performance. As I knew that performance will drop much after moving my VM on this little thing, I quickly made up my mind: performance is my priority. Also since I recently found a nice, tiny utility for Windows which I wanted to test, I had the perfect opportunity to do so.

My VM system disk (C:) was looking like this:

Drive C: Properties

Here is what I did next:

Benchmark #1

– format the SDXC card using HFSPlus
– copied entire “TestVM_Folder” under root
– start VM from SDXC then ran the Parkdale

Parkdale Default Settings

Windows 7 performance result

VirtualBox VDI (NTFS-inside) on top of HFSPlus

Benchmark #2

– format the SDXC card using NTFS
– copied entire “TestVM_Folder” under root
– start VM from SDXC then ran the Parkdale

Windows 7 performance result

VirtualBox VDI (NTFS-inside) on top of NTFS

Benchmark #3

– format the SDXC card using ExFAT
– copied entire “TestVM_Folder” under root
– start VM from SDXC then ran the Parkdale

Windows 7 performance result

VirtualBox VDI (NTFS-inside) on top of ExFAT


ExFAT is/was the best choice for me as my priority was performance.
One may go further and apply some well-known NTFS performance hacks.