Gee, that makes it sound like cloud-hosted products are susceptible to data center outages just like products that rely on colocated and contracted hosting. Impossible!
> does not necessarily mean you're actually writing out 20GB to the disk.
You mean like preallocation? I think Virtualbox now does that. In the past it didn't though, it just kept writing a bunch of zeroes to the drive until it reached 20GB.