I don't think disposable VMs run entirely in RAM. I have seen no mention of that, and if it was a feature, I expect to have read it somewhere. It isn't mentioned in any of the documentation that I've dug up (which is unfortunately sparse): http://qubes-os.org/trac/wiki/DisposableVms http://qubes-os.org/trac/wiki/UserDoc/DispVMCustomization http://theinvisiblethings.blogspot.com/2010/06/disposable-vms.html I'm not running Qubes right now because the hard drive crashed on the old laptop that I was testing it on, but you should be able to look at the properties of the dispvm in the VM Manager and see whether / how much disk storage space it has been assigned. A VM that runs only in RAM would be preferred, but I suppose it's not a big problem if you use full disk encryption. If someone has access to your decrypted hard drive, you are probably already screwed. Seems so, although you may be able to wipe the RAM of specific VMs too. IDK. I heard DDR3 memory decays very quickly anyway, so cold boot attacks are not very effective on it. All I can find about this issue re Qubes was this message from the qubes-devel mailing list: And then this roadmap: http://qubes-os.org/trac/roadmap which says that the trusted boot / anti-evil mail stuff won't be added until Qubes version 3, meaning it could be a few years before they include a memory wipe feature. I haven't tried this, but cat with redirection is supposed to do nothing in the terminal. Did you check if the file is in the destination location? Haven't tried this either. Can you get to check.torproject.org in a regular browser (through the TorVM)? If so, then maybe the script is blocking everything but onion addresses, which seems strange. Can you paste it here?