QEMU vs. VirtualBox
Why is it that the U.S. Government always releases a slew of RFPs just before Thanksgiving? I’ve been swamped working on proposals since the third week of November, but we got the last one submitted just before Christmas so it’s back to normal (or what passes for normal around here) for a while.
I thought I’d take this relatively quiet period to do a quickie comparison between a couple of virtualization tools: QEMU and Oracle's VirtualBox. For the comparison I chose to install virtual guest instances of Ubuntu 10.10 desktop from a downloaded copy of the iso. The host system is an AMD 64-bit machine that is also running Ubuntu 10.10 desktop. Here’s the kernel version of the host at the time of this writing: 2.6.35-24-generic #42-Ubuntu SMP Thu Dec 2 02:41:37 UTC 2010 x86_64 GNU/Linux. I used VirtualBox 4.0 for this comparison.
Both products provide a graphical interface for building a new virtual guest instance. Here are what a few of the QEMU build sequence steps look like:
This review almost did not get written, because it took friggen forever for the QEMU install to complete. It was only out of a somewhat morbid fascination that I let it go to completion. I started the install at about 8:15am in the morning, and by 1:00pm it was finally finished. By comparison, the VirtualBox install took just 28 minutes start to finish, and that included download time for updates, since I had selected the option to do that at install time. I did not select the update option for the QEMU install because I (fortunately) forgot to select NAT networking for it prior to starting the installation.
After the QEMU install was done, the Ubuntu guest remained equivalently slow. Boot time was about 6 minutes as compared to 23 seconds for the VirtualBox Ubuntu guest. Once I got the logon prompt from the QEMU guest it took a very long time to achieve the final QEMU result:
That’s right, a black screen. Which lasted so long I thought that was the final product. About 15 minutes later, though, I got a login prompt, which promised to take forever to execute, so I finally put it out of its misery.
Oracle does not need to be too worried about competition from the QEMU camp just yet...
------------------------------------------------ UPDATE: 1/15/2011 -- The performance problem has been fixed by completely removing the kvm and qemu-kvm packages and then reinstalling. Thanks to all the comments which helped me zero in on the problem. Also, at the suggestion of one reader, I reset the BIOS option for enabling virtualization and then power cycled the host. Not sure if that was necessary, but I did it anyhow.
Performance of the VMs are now as others have reported, with install times taking minutes rather than hours.