> I only recall two really serious vulnerabilities. Having a discriminating memory doesn't help you build programs that have no bugs. It only helps you feel be

> I only recall two really serious vulnerabilities. Having a discriminating memory doesn't help you build programs that have no bugs. It only helps you feel better about the bugs in the programs you create. Meanwhile, real users believe DoS are serious vulnerabilities. > If you place mail+web server on the same machine without a hypervisor, things can certainly be less secure than if you place multiple services on the same machine separated by the hypervisor. No. It isn't certain. The hypervisor is just more code. Why should anyone believe more code is going to produce less bugs? > The "memory sinkhole" problem does not apply to virtualization. Why do you think so? Users believed they could "place multiple services on the same machine separated by the hypervisor" would be more secure, and then it turned out they couldn't. If only they had used a simpler system they would have had actual security. This is evident. > It's about keeping web server bugs in the web server, and not have them infect the mail server. Wrong. A bug in the Linux PCI code affects web servers. A bug in ext4 affects a mail server. Don't you get it? Big programs have bugs.