Simulate a hard disk fail on Virtual Box

I'm testing some NAS setups using virtualbox, with several virtual hard drives, and software raid.

I would like to test the behavior under certain fails, and I would like to simulate that one of the hard disks broke and there's need to rebuild the RAID...

Would it be enough to do a

cat /proc/urandom > /virtualdisk

Or as the virtual disks are containers, VBox couldn't use it and would break the VirtualBox machine?

Answer

I don't know that you can fail a hard drive this way in VBox (or any VM -- They're typically designed to pretend hardware is perfect). You can try it and see but the results could be pretty awful...

A better strategy might be to shut down the VM & remove the disk, power on & do stuff, then shutdown & re-add the disk. Another option is to use the software RAID administration tools to mark a drive as failed (almost all of them support this AFAIK), scribble on it from within the VM, then re-add it & watch the rebuild.

All told however the only real test of a drive failure is to put the OS on real hardware and yank out one of the disks -- This is the only way to know for sure how your OS will react on a given piece of hardware with associated controller quirks.