Today, Sun released VirtualBox 2.1, and it seems that the new features really pack a punch. I wanted to share those new features and my thoughts on each.

First, the summarized new features according to the Changelog, with my personal favorites with emphasis:

• Support for hardware virtualization on Mac OS X hosts
• Support for 64-bit guests on 32-bit host operating systems
• Added support for Intel Nehalem virtualization enhancements
• Experimental 3D acceleration via OpenGL
• Experimental LsiLogic and BusLogic SCSI controllers
• Full VMDK/VHD support including snapshots
• New NAT engine with significantly better performance, reliability and ICMP echo (ping) support
• New Host Interface Networking implementations for Windows and Linux hosts with easier setup

Support for hardware virtualization on Mac OS X hosts

I don’t personally run OS X, but this is certainly a welcomed feature regardless. I’m a bit confused though, as Sun claims better speed with this turned off in many cases. However, this may no longer be true as I’ll get to later.

Support for 64-bit guests on 32-bit host operating systems

I wasn’t even aware this was possible – and my jaw dropped when I read this. I think this is a killer feature, especially with the continued move of server platforms to 64-bit only. Exchange 2007 immediately comes to mind – it will only run on a 64-bit version of Windows Server. You could now implement a headless 32-bit Linux host that in fact runs a 64-bit guest.

There are some easy-to-satisfy caveats to this, however:

1. 64-bit processor with hardware virtualization is required. You didn’t think you were going to run this on some old Pentium 4, did you?
2. Actually enable hardware virtualization! Requirement 1 exists for a reason, and that’s for Requirement 2. Go ahead and ensure that it is enabled in your BIOS and for the specific VM.
3. Select a 64-bit OS for the guest. Because of the extra overhead involved, VirtualBox requires that you explicitly request the support.
4. I/O APIC should be enabled for 64-bit Windows guests.
5. Intel networking devices should be used in place of AMD network devices for 64-bit Windows guests.

What it boils down to is this: If you’ve got a fairly recent processor, just flip a couple software switches and you’re home free.

I. LOVE. IT.

Added support for Intel Nehalem virtualization enhancements

Nice future-proofing, but doesn’t do much for many people right now. Still a welcome enhancement.

Experimental 3D acceleration via OpenGL

This helps bring the features closer inline with Parallels Desktop and VMware Fusion on the Mac. If you have an OpenGL application, VirtualBox will attempt to render that window using the host’s native OpenGL support, if available. The feature works regardless of host, which is great! Unfortunately, at this time, the guest must be Windows XP or Windows Vista 32-bit. Understandably, Guest Additions must be installed. Also, Direct3D is not currently supported. Lastly, this feature is deemed experimental and disabled by default. Enable it in the Advanced settings.

Experimental LsiLogic and BusLogic SCSI controllers

OK? I’m not sure who is this targeted at, but would like to know.

Full VMDK/VHD support including snapshots

Another godly feature! Previously, VirtualBox supported only its own custom VDI file format. I accepted this particular tradeoff because VirtualBox can run on any major OS; if you want to switch from Windows to Linux, just transport the VDI file and add it to the new VM.

Sun has removed yet another barrier to entry by supporting two new container formats. VMDK (used by VMware) and VHD (used by Microsoft Virtual PC).

New NAT engine with significantly better performance, reliability and ICMP echo (ping) support

Self-explanatory. I wouldn’t call this an enhancement as much as a bug fix, but the change is welcome nonetheless. I don’t personally use this, since I prefer Host networking… which brings us to:

New Host Interface Networking implementations for Windows and Linux hosts with easier setup

Currently, host networking is a pain to setup and get working correctly, 100% of the time. According to the new documentation, Linux and Windows hosts no longer you to manually bridge interfaces within the OS itself. A simple dropdown in VirtualBox will allow you to indicate which adapter to bind to.

There are a few limitations as outlined in the manual, most of which relate to wireless adapter support. Mac and Linux only support IPv4 over wireless and Solaris doesn’t support wireless at all. If this is a deal-breaker, consider setting up a wireless bridge using a router that supports DD-WRT.

Other Miscellaneous

“Significant performance improvements for VT-x”. This is the “I’ll get to later” in the first item. No benchmarks are available yet, but I wonder if this starts to negate some of the claim that VirtualBox performs better with hardware virtualization off rather than on. Especially with the requirements that it be turned on for some features, maybe there are large performance gains to be made as Sun invests more resources into this rather than their own custom tweaks.

Resources

If you need more detailed information, certainly give the VirtualBox User Manual [PDF] a read through.

As always, be sure to leave a comment if you’ve got anything to add.