I was just cloning a VDI file to try something out. I used to do this all the time, copy the harddisk file, then run "%ProgramFiles%\Oracle\VirtualBox\VBoxManage.exe" internalcommands sethduuid "cloned.vdi" to give it a new uuid, and finally creating a new virtual machine with the cloned harddisk.

Well, today it didn't work. Windows 7 kept failing to start, but the original virtual machine worked fine. Also the windows repair function couldn't repair it. Turned out that the new virtual machine put the cloned vdi under a sata controller. The old virtual machine had it under an ata controller. So I switched it back to ata, and now it starts up ok again!

I'm not sure why it now uses sata, instead of ata. I switched to a newer laptop, and at the same time to a new VirtualBox version, so it might be either one of those.

I recently started using VirtualBox as a replacement for VirtualPC 2007 to do builds using an old build environment. The NUnit test was failing, so I fixed the problem, compiled, and reran the test. Hmmm, still failing! Retried a couple of times, and then it hit me! NUnit didn't see the changed binaries when in VirtualBox. So I restarted NUnit, and presto! Tests are running again! Now I hope I won't forget next time...